Build complete FastAPI inventory management application

- Created FastAPI application structure with SQLAlchemy and Alembic
- Implemented full CRUD operations for inventory items
- Added search, filtering, and pagination capabilities
- Configured CORS, API documentation, and health endpoints
- Set up SQLite database with proper migrations
- Added comprehensive API documentation and README

README.md

@@ -1,3 +1,125 @@
-# FastAPI Application
+# Inventory Management API
 
-This is a FastAPI application bootstrapped by BackendIM, the AI-powered backend generation platform.
+A comprehensive FastAPI-based inventory management system for tracking and managing inventory items.
+
+## Features
+
+- **CRUD Operations**: Create, read, update, and delete inventory items
+- **Search & Filter**: Search by name, description, or SKU and filter by category
+- **Quantity Management**: Update item quantities with dedicated endpoint
+- **RESTful API**: Clean REST API endpoints with proper HTTP status codes
+- **Data Validation**: Pydantic models for request/response validation
+- **Database Migrations**: Alembic integration for database schema management
+- **API Documentation**: Auto-generated OpenAPI/Swagger documentation
+
+## Technology Stack
+
+- **Framework**: FastAPI
+- **Database**: SQLite with SQLAlchemy ORM
+- **Migrations**: Alembic
+- **Validation**: Pydantic
+- **Code Quality**: Ruff for linting and formatting
+
+## Project Structure
+
+```
+├── app/
+│   ├── api/
+│   │   └── inventory.py      # Inventory API endpoints
+│   ├── db/
+│   │   ├── base.py          # SQLAlchemy base model
+│   │   └── session.py       # Database session configuration
+│   ├── models/
+│   │   └── inventory.py     # SQLAlchemy models
+│   └── schemas/
+│       └── inventory.py     # Pydantic schemas
+├── migrations/              # Alembic migration files
+├── main.py                 # FastAPI application entry point
+├── requirements.txt        # Python dependencies
+└── alembic.ini            # Alembic configuration
+```
+
+## Installation
+
+1. Install dependencies:
+```bash
+pip install -r requirements.txt
+```
+
+2. Run database migrations:
+```bash
+alembic upgrade head
+```
+
+3. Start the development server:
+```bash
+uvicorn main:app --reload
+```
+
+The API will be available at `http://localhost:8000`
+
+## API Endpoints
+
+### Base Endpoints
+- `GET /` - API information and links
+- `GET /health` - Health check endpoint
+
+### Inventory Management
+- `GET /api/v1/inventory/` - List all inventory items (with pagination, search, and filtering)
+- `GET /api/v1/inventory/{item_id}` - Get specific inventory item
+- `POST /api/v1/inventory/` - Create new inventory item
+- `PUT /api/v1/inventory/{item_id}` - Update inventory item
+- `DELETE /api/v1/inventory/{item_id}` - Delete inventory item
+- `PATCH /api/v1/inventory/{item_id}/quantity` - Update item quantity
+
+### Query Parameters
+- `skip` - Number of records to skip (pagination)
+- `limit` - Maximum number of records to return
+- `category` - Filter by category
+- `search` - Search in name, description, or SKU
+
+## API Documentation
+
+Once the server is running, you can access:
+- Swagger UI: `http://localhost:8000/docs`
+- ReDoc: `http://localhost:8000/redoc`
+- OpenAPI JSON: `http://localhost:8000/openapi.json`
+
+## Data Model
+
+### Inventory Item
+```json
+{
+  "id": 1,
+  "name": "Product Name",
+  "description": "Product description",
+  "sku": "UNIQUE-SKU-123",
+  "quantity": 50,
+  "price": 29.99,
+  "category": "Electronics",
+  "supplier": "Supplier Name",
+  "location": "Warehouse A",
+  "created_at": "2024-01-01T00:00:00Z",
+  "updated_at": "2024-01-01T00:00:00Z"
+}
+```
+
+## Development
+
+### Code Quality
+The project uses Ruff for code formatting and linting:
+```bash
+ruff check .
+ruff format .
+```
+
+### Database Migrations
+To create a new migration after model changes:
+```bash
+alembic revision --autogenerate -m "Description of changes"
+alembic upgrade head
+```
+
+## Storage
+
+The application uses `/app/storage/db/` as the database storage directory with SQLite. The database file will be created automatically at `/app/storage/db/db.sqlite`.

alembic.ini

@@ -0,0 +1,41 @@
+[alembic]
+script_location = migrations
+prepend_sys_path = .
+version_path_separator = os
+sqlalchemy.url = sqlite:////app/storage/db/db.sqlite
+
+[post_write_hooks]
+
+[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/inventory.py

@@ -0,0 +1,106 @@
+from typing import List, Optional
+from fastapi import APIRouter, Depends, HTTPException, Query
+from sqlalchemy.orm import Session
+from app.db.session import get_db
+from app.models.inventory import InventoryItem
+from app.schemas.inventory import (
+    InventoryItem as InventoryItemSchema,
+    InventoryItemCreate,
+    InventoryItemUpdate,
+)
+
+router = APIRouter()
+
+
+@router.get("/", response_model=List[InventoryItemSchema])
+def get_inventory_items(
+    skip: int = Query(0, ge=0),
+    limit: int = Query(100, ge=1, le=1000),
+    category: Optional[str] = Query(None),
+    search: Optional[str] = Query(None),
+    db: Session = Depends(get_db),
+):
+    query = db.query(InventoryItem)
+    
+    if category:
+        query = query.filter(InventoryItem.category == category)
+    
+    if search:
+        query = query.filter(
+            (InventoryItem.name.contains(search)) |
+            (InventoryItem.description.contains(search)) |
+            (InventoryItem.sku.contains(search))
+        )
+    
+    items = query.offset(skip).limit(limit).all()
+    return items
+
+
+@router.get("/{item_id}", response_model=InventoryItemSchema)
+def get_inventory_item(item_id: int, db: Session = Depends(get_db)):
+    item = db.query(InventoryItem).filter(InventoryItem.id == item_id).first()
+    if not item:
+        raise HTTPException(status_code=404, detail="Inventory item not found")
+    return item
+
+
+@router.post("/", response_model=InventoryItemSchema)
+def create_inventory_item(item: InventoryItemCreate, db: Session = Depends(get_db)):
+    existing_item = db.query(InventoryItem).filter(InventoryItem.sku == item.sku).first()
+    if existing_item:
+        raise HTTPException(status_code=400, detail="SKU already exists")
+    
+    db_item = InventoryItem(**item.model_dump())
+    db.add(db_item)
+    db.commit()
+    db.refresh(db_item)
+    return db_item
+
+
+@router.put("/{item_id}", response_model=InventoryItemSchema)
+def update_inventory_item(
+    item_id: int, item_update: InventoryItemUpdate, db: Session = Depends(get_db)
+):
+    db_item = db.query(InventoryItem).filter(InventoryItem.id == item_id).first()
+    if not db_item:
+        raise HTTPException(status_code=404, detail="Inventory item not found")
+    
+    if item_update.sku and item_update.sku != db_item.sku:
+        existing_item = db.query(InventoryItem).filter(InventoryItem.sku == item_update.sku).first()
+        if existing_item:
+            raise HTTPException(status_code=400, detail="SKU already exists")
+    
+    update_data = item_update.model_dump(exclude_unset=True)
+    for field, value in update_data.items():
+        setattr(db_item, field, value)
+    
+    db.commit()
+    db.refresh(db_item)
+    return db_item
+
+
+@router.delete("/{item_id}")
+def delete_inventory_item(item_id: int, db: Session = Depends(get_db)):
+    db_item = db.query(InventoryItem).filter(InventoryItem.id == item_id).first()
+    if not db_item:
+        raise HTTPException(status_code=404, detail="Inventory item not found")
+    
+    db.delete(db_item)
+    db.commit()
+    return {"message": "Inventory item deleted successfully"}
+
+
+@router.patch("/{item_id}/quantity")
+def update_item_quantity(
+    item_id: int, 
+    quantity: int = Query(..., ge=0),
+    db: Session = Depends(get_db)
+):
+    db_item = db.query(InventoryItem).filter(InventoryItem.id == item_id).first()
+    if not db_item:
+        raise HTTPException(status_code=404, detail="Inventory item not found")
+    
+    db_item.quantity = quantity
+    db.commit()
+    db.refresh(db_item)
+    return {"message": f"Quantity updated to {quantity}", "item": db_item}

app/db/base.py

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+from sqlalchemy.ext.declarative import declarative_base
+
+Base = declarative_base()

app/db/session.py

@@ -0,0 +1,23 @@
+from pathlib import Path
+from sqlalchemy import create_engine
+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)
+
+
+def get_db():
+    db = SessionLocal()
+    try:
+        yield db
+    finally:
+        db.close()

app/models/__init__.py

@@ -0,0 +1,3 @@
+from .inventory import InventoryItem
+
+__all__ = ["InventoryItem"]

app/models/inventory.py

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+from sqlalchemy import Column, Integer, String, Float, DateTime, Text
+from sqlalchemy.sql import func
+from app.db.base import Base
+
+
+class InventoryItem(Base):
+    __tablename__ = "inventory_items"
+
+    id = Column(Integer, primary_key=True, index=True)
+    name = Column(String(255), nullable=False, index=True)
+    description = Column(Text, nullable=True)
+    sku = Column(String(100), unique=True, nullable=False, index=True)
+    quantity = Column(Integer, nullable=False, default=0)
+    price = Column(Float, nullable=False)
+    category = Column(String(100), nullable=True, index=True)
+    supplier = Column(String(255), nullable=True)
+    location = Column(String(255), nullable=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 +1,3 @@
+from .inventory import InventoryItem, InventoryItemCreate, InventoryItemUpdate, InventoryItemBase
+
+__all__ = ["InventoryItem", "InventoryItemCreate", "InventoryItemUpdate", "InventoryItemBase"]

app/schemas/inventory.py

@@ -0,0 +1,38 @@
+from datetime import datetime
+from typing import Optional
+from pydantic import BaseModel, Field
+
+
+class InventoryItemBase(BaseModel):
+    name: str = Field(..., min_length=1, max_length=255)
+    description: Optional[str] = None
+    sku: str = Field(..., min_length=1, max_length=100)
+    quantity: int = Field(..., ge=0)
+    price: float = Field(..., gt=0)
+    category: Optional[str] = Field(None, max_length=100)
+    supplier: Optional[str] = Field(None, max_length=255)
+    location: Optional[str] = Field(None, max_length=255)
+
+
+class InventoryItemCreate(InventoryItemBase):
+    pass
+
+
+class InventoryItemUpdate(BaseModel):
+    name: Optional[str] = Field(None, min_length=1, max_length=255)
+    description: Optional[str] = None
+    sku: Optional[str] = Field(None, min_length=1, max_length=100)
+    quantity: Optional[int] = Field(None, ge=0)
+    price: Optional[float] = Field(None, gt=0)
+    category: Optional[str] = Field(None, max_length=100)
+    supplier: Optional[str] = Field(None, max_length=255)
+    location: Optional[str] = Field(None, max_length=255)
+
+
+class InventoryItem(InventoryItemBase):
+    id: int
+    created_at: datetime
+    updated_at: datetime
+
+    class Config:
+        from_attributes = True

main.py

@@ -0,0 +1,40 @@
+from fastapi import FastAPI
+from fastapi.middleware.cors import CORSMiddleware
+from fastapi.responses import JSONResponse
+from app.api.inventory import router as inventory_router
+
+app = FastAPI(
+    title="Inventory Management API",
+    description="A comprehensive inventory management system",
+    version="1.0.0",
+    openapi_url="/openapi.json",
+)
+
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=["*"],
+    allow_credentials=True,
+    allow_methods=["*"],
+    allow_headers=["*"],
+)
+
+app.include_router(inventory_router, prefix="/api/v1/inventory", tags=["inventory"])
+
+
+@app.get("/")
+async def root():
+    return {
+        "title": "Inventory Management API",
+        "description": "A comprehensive inventory management system",
+        "version": "1.0.0",
+        "documentation": "/docs",
+        "health_check": "/health"
+    }
+
+
+@app.get("/health")
+async def health_check():
+    return {
+        "status": "healthy",
+        "message": "Inventory Management API is running properly"
+    }

migrations/env.py

@@ -0,0 +1,55 @@
+import os
+import sys
+from logging.config import fileConfig
+from sqlalchemy import engine_from_config
+from sqlalchemy import pool
+from alembic import context
+
+sys.path.append(os.path.dirname(os.path.dirname(__file__)))
+
+from app.db.base import Base
+from app.models import *
+
+config = context.config
+
+if config.config_file_name is not None:
+    fileConfig(config.config_file_name)
+
+target_metadata = Base.metadata
+
+
+def run_migrations_offline() -> None:
+    """Run migrations in 'offline' mode."""
+    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() -> None:
+    """Run migrations in 'online' mode."""
+    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 +1,23 @@
+"""${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 = ${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/001_create_inventory_items_table.py

@@ -0,0 +1,44 @@
+"""Create inventory items table
+
+Revision ID: 001
+Revises: 
+Create Date: 2024-01-01 00:00:00.000000
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+revision = '001'
+down_revision = None
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    op.create_table(
+        'inventory_items',
+        sa.Column('id', sa.Integer(), nullable=False),
+        sa.Column('name', sa.String(length=255), nullable=False),
+        sa.Column('description', sa.Text(), nullable=True),
+        sa.Column('sku', sa.String(length=100), nullable=False),
+        sa.Column('quantity', sa.Integer(), nullable=False),
+        sa.Column('price', sa.Float(), nullable=False),
+        sa.Column('category', sa.String(length=100), nullable=True),
+        sa.Column('supplier', sa.String(length=255), nullable=True),
+        sa.Column('location', sa.String(length=255), nullable=True),
+        sa.Column('created_at', sa.DateTime(timezone=True), server_default=sa.text('CURRENT_TIMESTAMP'), nullable=True),
+        sa.Column('updated_at', sa.DateTime(timezone=True), server_default=sa.text('CURRENT_TIMESTAMP'), nullable=True),
+        sa.PrimaryKeyConstraint('id')
+    )
+    op.create_index(op.f('ix_inventory_items_id'), 'inventory_items', ['id'], unique=False)
+    op.create_index(op.f('ix_inventory_items_name'), 'inventory_items', ['name'], unique=False)
+    op.create_index(op.f('ix_inventory_items_sku'), 'inventory_items', ['sku'], unique=True)
+    op.create_index(op.f('ix_inventory_items_category'), 'inventory_items', ['category'], unique=False)
+
+
+def downgrade() -> None:
+    op.drop_index(op.f('ix_inventory_items_category'), table_name='inventory_items')
+    op.drop_index(op.f('ix_inventory_items_sku'), table_name='inventory_items')
+    op.drop_index(op.f('ix_inventory_items_name'), table_name='inventory_items')
+    op.drop_index(op.f('ix_inventory_items_id'), table_name='inventory_items')
+    op.drop_table('inventory_items')

pyproject.toml

@@ -0,0 +1,11 @@
+[tool.ruff]
+line-length = 88
+target-version = "py39"
+
+[tool.ruff.lint]
+select = ["E", "F", "W", "C", "I"]
+ignore = ["E501"]
+
+[tool.ruff.format]
+quote-style = "double"
+indent-style = "space"

requirements.txt

@@ -0,0 +1,7 @@
+fastapi==0.104.1
+uvicorn[standard]==0.24.0
+sqlalchemy==2.0.23
+alembic==1.12.1
+python-multipart==0.0.6
+pydantic==2.5.0
+ruff==0.1.6