Complete Todo API implementation with FastAPI and SQLite

- Add SQLite database configuration
- Create Todo model, schemas, and CRUD operations
- Implement Todo API endpoints
- Add Alembic migration for todo table
- Set up database initialization in main.py
- Update README with project details and instructions
- Add pyproject.toml with Ruff configuration

README.md

@@ -1,3 +1,68 @@
-# FastAPI Application
+# Todo API
 
-This is a FastAPI application bootstrapped by BackendIM, the AI-powered backend generation platform.
+This is a FastAPI Todo API application that allows you to manage todo items.
+
+## Features
+
+- Create, read, update, and delete todo items
+- Filter todos by completion status and title
+- Pagination support
+- SQLite database backend
+- Alembic migrations
+
+## Requirements
+
+- Python 3.9+
+- FastAPI
+- SQLAlchemy
+- Alembic
+- Uvicorn
+- Other dependencies in requirements.txt
+
+## Installation
+
+1. Clone the repository
+2. Install the dependencies:
+
+```bash
+pip install -r requirements.txt
+```
+
+## Database Setup
+
+The application uses SQLite as the database backend. The database will be automatically created in the `/app/storage/db` directory when the application starts.
+
+To run the database migrations:
+
+```bash
+alembic upgrade head
+```
+
+## Running the Application
+
+Start the application with Uvicorn:
+
+```bash
+uvicorn main:app --reload
+```
+
+The API will be available at http://localhost:8000
+
+## API Documentation
+
+The API documentation is available at:
+
+- Swagger UI: http://localhost:8000/docs
+- ReDoc: http://localhost:8000/redoc
+
+## API Endpoints
+
+- `GET /api/v1/todos`: List all todos with optional filtering
+- `POST /api/v1/todos`: Create a new todo
+- `GET /api/v1/todos/{todo_id}`: Get a specific todo
+- `PUT /api/v1/todos/{todo_id}`: Update a todo
+- `DELETE /api/v1/todos/{todo_id}`: Delete a todo
+
+## Health Check
+
+The application includes a health check endpoint at `/health` that can be used to verify that the service is running properly.

alembic.ini

@@ -0,0 +1,74 @@
+# 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
+
+# timezone to use when rendering the date
+# within the migration file as well as the filename.
+# 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
+# version_locations = %(here)s/bar %(here)s/bat migrations/versions
+
+# the output encoding used when revision files
+# are written from script.py.mako
+# output_encoding = utf-8
+
+# SQLite URL using absolute path
+sqlalchemy.url = sqlite:////app/storage/db/db.sqlite
+
+# 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_v1/api.py

@@ -0,0 +1,6 @@
+from fastapi import APIRouter
+
+from app.api.api_v1.endpoints import todos
+
+api_router = APIRouter()
+api_router.include_router(todos.router, prefix="/todos", tags=["todos"])

app/api/api_v1/endpoints/todos.py

@@ -0,0 +1,110 @@
+from typing import Any, Optional
+
+from fastapi import APIRouter, Depends, HTTPException, status
+from sqlalchemy.orm import Session
+
+from app.api.deps import get_db
+from app.crud import todo as crud_todo
+from app.schemas.todo import Todo, TodoCreate, TodoList, TodoUpdate
+
+router = APIRouter()
+
+
+@router.get("/", response_model=TodoList)
+def read_todos(
+    db: Session = Depends(get_db),
+    skip: int = 0,
+    limit: int = 100,
+    completed: Optional[bool] = None,
+    title: Optional[str] = None,
+) -> Any:
+    """
+    Retrieve todos.
+    
+    - **skip**: Number of records to skip for pagination
+    - **limit**: Maximum number of records to return
+    - **completed**: Filter by completion status
+    - **title**: Filter by title (partial match)
+    """
+    filters = {}
+    if completed is not None:
+        filters["completed"] = completed
+    if title:
+        filters["title"] = title
+        
+    todos = crud_todo.get_multi(db, skip=skip, limit=limit, filters=filters)
+    count = crud_todo.count(db, filters=filters)
+    return {"items": todos, "count": count}
+
+
+@router.post("/", response_model=Todo, status_code=status.HTTP_201_CREATED)
+def create_todo(
+    *,
+    db: Session = Depends(get_db),
+    todo_in: TodoCreate,
+) -> Any:
+    """
+    Create new todo.
+    """
+    todo = crud_todo.create(db, obj_in=todo_in)
+    return todo
+
+
+@router.get("/{todo_id}", response_model=Todo)
+def read_todo(
+    *,
+    db: Session = Depends(get_db),
+    todo_id: int,
+) -> Any:
+    """
+    Get todo by ID.
+    """
+    todo = crud_todo.get(db, todo_id=todo_id)
+    if not todo:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="Todo not found"
+        )
+    return todo
+
+
+@router.put("/{todo_id}", response_model=Todo)
+def update_todo(
+    *,
+    db: Session = Depends(get_db),
+    todo_id: int,
+    todo_in: TodoUpdate,
+) -> Any:
+    """
+    Update a todo.
+    """
+    todo = crud_todo.get(db, todo_id=todo_id)
+    if not todo:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="Todo not found"
+        )
+    todo = crud_todo.update(db, db_obj=todo, obj_in=todo_in)
+    return todo
+
+
+@router.delete(
+    "/{todo_id}", 
+    status_code=status.HTTP_204_NO_CONTENT, 
+    response_model=None
+)
+def delete_todo(
+    *,
+    db: Session = Depends(get_db),
+    todo_id: int,
+) -> None:
+    """
+    Delete a todo.
+    """
+    todo = crud_todo.get(db, todo_id=todo_id)
+    if not todo:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="Todo not found"
+        )
+    crud_todo.remove(db, todo_id=todo_id)

app/api/deps.py

@@ -0,0 +1,14 @@
+from collections.abc import Generator
+
+from app.db.session import SessionLocal
+
+
+def get_db() -> Generator:
+    """
+    Dependency for getting the database session.
+    """
+    db = SessionLocal()
+    try:
+        yield db
+    finally:
+        db.close()

app/core/config.py

@@ -0,0 +1,26 @@
+from pydantic import validator
+from pydantic_settings import BaseSettings
+
+
+class Settings(BaseSettings):
+    API_V1_STR: str = "/api/v1"
+    PROJECT_NAME: str = "Todo API"
+    VERSION: str = "0.1.0"
+    
+    # CORS Configuration
+    BACKEND_CORS_ORIGINS: list[str] = ["*"]
+
+    @validator("BACKEND_CORS_ORIGINS", pre=True)
+    def assemble_cors_origins(cls, v: list[str]) -> list[str]:
+        if isinstance(v, str) and not v.startswith("["):
+            return [i.strip() for i in v.split(",")]
+        elif isinstance(v, (list, str)):
+            return v
+        raise ValueError(v)
+
+    class Config:
+        env_file = ".env"
+        case_sensitive = True
+
+
+settings = Settings()

app/crud/todo.py

@@ -0,0 +1,145 @@
+from typing import Any, Dict, Optional, Union
+
+from sqlalchemy.orm import Session
+
+from app.models.todo import Todo
+from app.schemas.todo import TodoCreate, TodoUpdate
+
+
+def get(db: Session, todo_id: int) -> Optional[Todo]:
+    """
+    Get a single todo item by ID.
+    
+    Args:
+        db: Database session
+        todo_id: ID of the todo item to retrieve
+        
+    Returns:
+        Todo object if found, None otherwise
+    """
+    return db.query(Todo).filter(Todo.id == todo_id).first()
+
+
+def get_multi(
+    db: Session, 
+    *, 
+    skip: int = 0, 
+    limit: int = 100, 
+    filters: Optional[Dict[str, Any]] = None
+) -> list[Todo]:
+    """
+    Get multiple todo items with optional filtering, pagination.
+    
+    Args:
+        db: Database session
+        skip: Number of records to skip (for pagination)
+        limit: Maximum number of records to return
+        filters: Optional dictionary of filter conditions
+        
+    Returns:
+        List of Todo objects
+    """
+    query = db.query(Todo)
+    
+    # Apply filters if provided
+    if filters:
+        if "completed" in filters:
+            query = query.filter(Todo.completed == filters["completed"])
+            
+        if "title" in filters:
+            query = query.filter(Todo.title.ilike(f"%{filters['title']}%"))
+    
+    return query.order_by(Todo.created_at.desc()).offset(skip).limit(limit).all()
+
+
+def create(db: Session, *, obj_in: TodoCreate) -> Todo:
+    """
+    Create a new todo item.
+    
+    Args:
+        db: Database session
+        obj_in: TodoCreate schema with the data for the new todo
+        
+    Returns:
+        Created Todo object
+    """
+    db_obj = Todo(
+        title=obj_in.title,
+        description=obj_in.description,
+        completed=obj_in.completed,
+    )
+    db.add(db_obj)
+    db.commit()
+    db.refresh(db_obj)
+    return db_obj
+
+
+def update(
+    db: Session, *, db_obj: Todo, obj_in: Union[TodoUpdate, Dict[str, Any]]
+) -> Todo:
+    """
+    Update a todo item.
+    
+    Args:
+        db: Database session
+        db_obj: Existing Todo object to update
+        obj_in: TodoUpdate schema or dict with fields to update
+        
+    Returns:
+        Updated Todo object
+    """
+    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 field in update_data:
+            setattr(db_obj, field, update_data[field])
+            
+    db.add(db_obj)
+    db.commit()
+    db.refresh(db_obj)
+    return db_obj
+
+
+def remove(db: Session, *, todo_id: int) -> Optional[Todo]:
+    """
+    Delete a todo item.
+    
+    Args:
+        db: Database session
+        todo_id: ID of the todo item to delete
+        
+    Returns:
+        Deleted Todo object if found, None otherwise
+    """
+    obj = db.query(Todo).get(todo_id)
+    if obj:
+        db.delete(obj)
+        db.commit()
+    return obj
+
+
+def count(db: Session, *, filters: Optional[Dict[str, Any]] = None) -> int:
+    """
+    Count todo items with optional filtering.
+    
+    Args:
+        db: Database session
+        filters: Optional dictionary of filter conditions
+        
+    Returns:
+        Count of Todo objects matching the filters
+    """
+    query = db.query(Todo)
+    
+    # Apply filters if provided
+    if filters:
+        if "completed" in filters:
+            query = query.filter(Todo.completed == filters["completed"])
+            
+        if "title" in filters:
+            query = query.filter(Todo.title.ilike(f"%{filters['title']}%"))
+    
+    return query.count()

app/db/__init__.py

@@ -0,0 +1,2 @@
+# Import for convenience
+from app.db.base import Base

app/db/all_models.py

@@ -0,0 +1,2 @@
+# Import all models here for Alembic's sake
+# Import models below

app/db/base.py

@@ -0,0 +1,4 @@
+from sqlalchemy.ext.declarative import declarative_base
+
+# Define the SQLAlchemy base
+Base = declarative_base()

app/db/base_class.py

@@ -0,0 +1,15 @@
+from datetime import datetime
+
+from sqlalchemy import Column, DateTime
+from sqlalchemy.ext.declarative import declared_attr
+
+
+class BaseClass:
+    # Generate __tablename__ automatically based on class name
+    @declared_attr
+    def __tablename__(cls) -> str:
+        return cls.__name__.lower()
+    
+    # Add created_at and updated_at columns to all models
+    created_at = Column(DateTime, default=datetime.utcnow)
+    updated_at = Column(DateTime, default=datetime.utcnow, onupdate=datetime.utcnow)

app/db/session.py

@@ -0,0 +1,17 @@
+from pathlib import Path
+
+from sqlalchemy import create_engine
+from sqlalchemy.orm import sessionmaker
+
+# Create a storage directory for the SQLite database
+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)

app/models/todo.py

@@ -0,0 +1,14 @@
+from sqlalchemy import Boolean, Column, Integer, String, Text
+
+from app.db.base import Base
+from app.db.base_class import BaseClass
+
+
+class Todo(Base, BaseClass):
+    """
+    SQLAlchemy model for Todo items.
+    """
+    id = Column(Integer, primary_key=True, index=True)
+    title = Column(String(255), nullable=False, index=True)
+    description = Column(Text, nullable=True)
+    completed = Column(Boolean, default=False, nullable=False)

app/schemas/todo.py

@@ -0,0 +1,79 @@
+from datetime import datetime
+from typing import Optional
+
+from pydantic import BaseModel, Field
+
+
+class TodoBase(BaseModel):
+    """
+    Base schema for Todo items with common attributes.
+    """
+    title: str = Field(
+        ..., 
+        min_length=1, 
+        max_length=255, 
+        description="The title of the todo item"
+    )
+    description: Optional[str] = Field(
+        None, 
+        description="An optional detailed description of the todo item"
+    )
+    completed: bool = Field(
+        False, 
+        description="Whether the todo item has been completed"
+    )
+
+
+class TodoCreate(TodoBase):
+    """
+    Schema for creating a new Todo item.
+    """
+    pass
+
+
+class TodoUpdate(BaseModel):
+    """
+    Schema for updating an existing Todo item.
+    All fields are optional to allow partial updates.
+    """
+    title: Optional[str] = Field(
+        None, 
+        min_length=1, 
+        max_length=255, 
+        description="The title of the todo item"
+    )
+    description: Optional[str] = Field(
+        None, 
+        description="An optional detailed description of the todo item"
+    )
+    completed: Optional[bool] = Field(
+        None, 
+        description="Whether the todo item has been completed"
+    )
+
+
+class TodoInDBBase(TodoBase):
+    """
+    Schema for Todo items as stored in the database.
+    """
+    id: int
+    created_at: datetime
+    updated_at: datetime
+
+    class Config:
+        from_attributes = True
+
+
+class Todo(TodoInDBBase):
+    """
+    Schema for Todo items returned to the client.
+    """
+    pass
+
+
+class TodoList(BaseModel):
+    """
+    Schema for a list of Todo items.
+    """
+    items: list[Todo]
+    count: int

main.py

@@ -0,0 +1,89 @@
+import logging
+
+from fastapi import FastAPI
+from fastapi.middleware.cors import CORSMiddleware
+from fastapi.openapi.utils import get_openapi
+
+from app.api.api_v1.api import api_router
+from app.core.config import settings
+from app.db.base import Base
+from app.db.session import engine
+
+# Set up logging
+logging.basicConfig(level=logging.INFO)
+logger = logging.getLogger(__name__)
+
+# Create database tables
+def create_tables():
+    try:
+        logger.info("Creating database tables")
+        # Import all models to ensure they are registered with Base
+        from app.db.all_models import *  # noqa
+        Base.metadata.create_all(bind=engine)
+        logger.info("Database tables created successfully")
+    except Exception as e:
+        logger.error(f"Error creating database tables: {e}")
+        raise
+
+# Initialize FastAPI app
+app = FastAPI(
+    title=settings.PROJECT_NAME,
+    openapi_url="/openapi.json",
+    docs_url="/docs",
+    redoc_url="/redoc",
+)
+
+# Set all CORS enabled origins
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=["*"],
+    allow_credentials=True,
+    allow_methods=["*"],
+    allow_headers=["*"],
+)
+
+# Include API router
+app.include_router(api_router, prefix=settings.API_V1_STR)
+
+# Create tables on startup if they don't exist
+@app.on_event("startup")
+async def startup_event():
+    create_tables()
+
+
+@app.get("/", tags=["status"])
+async def root():
+    """
+    Root endpoint that returns basic service information.
+    """
+    return {
+        "name": settings.PROJECT_NAME,
+        "docs": "/docs",
+        "health": "/health"
+    }
+
+
+@app.get("/health", tags=["status"])
+async def health():
+    """
+    Health check endpoint.
+    """
+    return {"status": "healthy"}
+
+
+def custom_openapi():
+    if app.openapi_schema:
+        return app.openapi_schema
+    
+    openapi_schema = get_openapi(
+        title=settings.PROJECT_NAME,
+        version=settings.VERSION,
+        description="A FastAPI Todo API",
+        routes=app.routes,
+    )
+    
+    app.openapi_schema = openapi_schema
+    return app.openapi_schema
+
+
+app.openapi = custom_openapi

migrations/env.py

@@ -0,0 +1,77 @@
+import sys
+from logging.config import fileConfig
+from pathlib import Path
+
+from alembic import context
+from sqlalchemy import engine_from_config, pool
+
+# Add the parent directory to sys.path
+sys.path.append(str(Path(__file__).resolve().parents[1]))
+
+# Import the Base class from our app
+from app.db.base import Base  # noqa
+# Import all the models so that Alembic can see them
+from app.db.all_models import *  # noqa
+
+# This is the Alembic Config object
+config = context.config
+
+# Interpret the config file for Python logging
+fileConfig(config.config_file_name)
+
+# Set the target metadata for the database
+target_metadata = Base.metadata
+
+
+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,  # For SQLite
+    )
+
+    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,  # For 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():
+    ${upgrades if upgrades else "pass"}
+
+
+def downgrade():
+    ${downgrades if downgrades else "pass"}

migrations/versions/7f2ea9b3e5c8_create_todo_table.py

@@ -0,0 +1,42 @@
+"""create todo table
+
+Revision ID: 7f2ea9b3e5c8
+Revises: 
+Create Date: 2023-06-10 16:00:00.000000
+
+"""
+import sqlalchemy as sa
+from alembic import op
+
+# revision identifiers, used by Alembic.
+revision = '7f2ea9b3e5c8'
+down_revision = None
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # Create the todo table
+    op.create_table(
+        'todo',
+        sa.Column('id', sa.Integer(), nullable=False),
+        sa.Column('title', sa.String(length=255), nullable=False),
+        sa.Column('description', sa.Text(), nullable=True),
+        sa.Column('completed', sa.Boolean(), nullable=False, default=False),
+        sa.Column('created_at', sa.DateTime(), nullable=True),
+        sa.Column('updated_at', sa.DateTime(), nullable=True),
+        sa.PrimaryKeyConstraint('id')
+    )
+    
+    # Create an index on the title column
+    op.create_index(op.f('ix_todo_id'), 'todo', ['id'], unique=False)
+    op.create_index(op.f('ix_todo_title'), 'todo', ['title'], unique=False)
+
+
+def downgrade():
+    # Drop the indexes
+    op.drop_index(op.f('ix_todo_title'), table_name='todo')
+    op.drop_index(op.f('ix_todo_id'), table_name='todo')
+    
+    # Drop the todo table
+    op.drop_table('todo')

pyproject.toml

@@ -0,0 +1,37 @@
+[build-system]
+requires = ["setuptools>=61.0"]
+build-backend = "setuptools.build_meta"
+
+[project]
+name = "todoapi"
+version = "0.1.0"
+description = "FastAPI Todo API"
+readme = "README.md"
+requires-python = ">=3.9"
+classifiers = [
+    "Programming Language :: Python :: 3",
+    "License :: OSI Approved :: MIT License",
+    "Operating System :: OS Independent",
+]
+
+[tool.ruff]
+# Same as Black.
+line-length = 88
+indent-width = 4
+
+# Target Python 3.9.
+target-version = "py39"
+
+[tool.ruff.lint]
+# Enable pycodestyle ('E'), Pyflakes ('F'), isort ('I')
+select = ["E", "F", "I"]
+ignore = []
+
+# Allow unused variables when underscore-prefixed.
+dummy-variable-rgx = "^(_+|(_+[a-zA-Z0-9_]*[a-zA-Z0-9]+?))$"
+
+[tool.ruff.lint.per-file-ignores]
+"__init__.py" = ["F401"]
+
+[tool.ruff.lint.isort]
+known-third-party = ["fastapi", "pydantic", "sqlalchemy", "alembic"]

requirements.txt

@@ -0,0 +1,8 @@
+fastapi>=0.104.0
+uvicorn>=0.24.0
+sqlalchemy>=2.0.0
+alembic>=1.12.0
+pydantic>=2.4.2
+pydantic-settings>=2.0.3
+python-dotenv>=1.0.0
+ruff>=0.1.3