Create simple todo app with FastAPI and SQLite

README.md

@@ -1,3 +1,69 @@
-# FastAPI Application
+# Simple Todo App
 
-This is a FastAPI application bootstrapped by BackendIM, the AI-powered backend generation platform.
+A simple todo application built with FastAPI and SQLite.
+
+## Features
+
+- RESTful API for managing todo items
+- Create, read, update, and delete todo items
+- Health check endpoint
+- SQLite database with SQLAlchemy ORM
+- Database migrations with Alembic
+- Proper error handling and validation
+- API documentation with Swagger and ReDoc
+
+## Project Structure
+
+```
+├── app/                    # Application package
+│   ├── api/                # API endpoints
+│   │   └── v1/             # API version 1
+│   │       └── endpoints/  # API endpoint modules
+│   ├── core/               # Core modules
+│   ├── crud/               # CRUD operations
+│   ├── db/                 # Database modules
+│   ├── models/             # SQLAlchemy models
+│   └── schemas/            # Pydantic schemas
+├── migrations/             # Alembic migrations
+├── alembic.ini             # Alembic configuration
+├── main.py                 # Application entry point
+└── requirements.txt        # Python dependencies
+```
+
+## Installation
+
+1. Clone the repository
+2. Install dependencies:
+
+```bash
+pip install -r requirements.txt
+```
+
+## Running the Application
+
+Start the application with:
+
+```bash
+uvicorn main:app --reload
+```
+
+The API will be available at http://localhost:8000
+
+## API Documentation
+
+- Swagger UI: http://localhost:8000/docs
+- ReDoc: http://localhost:8000/redoc
+
+## API Endpoints
+
+### Health Check
+
+- `GET /health` - Check if the API is running
+
+### Todo Endpoints
+
+- `GET /todos` - Get all todos (with pagination)
+- `POST /todos` - Create a new todo
+- `GET /todos/{todo_id}` - Get a specific todo
+- `PUT /todos/{todo_id}` - Update a todo
+- `DELETE /todos/{todo_id}` - Delete a todo

alembic.ini

@@ -0,0 +1,86 @@
+# 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
+
+# Absolute path for SQLite database
+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/routes.py

@@ -0,0 +1,9 @@
+from fastapi import APIRouter
+
+from app.api.v1.endpoints import health, todos
+
+router = APIRouter()
+
+# Include sub-routers
+router.include_router(health.router, tags=["health"])
+router.include_router(todos.router, prefix="/todos", tags=["todos"])

app/api/v1/endpoints/health.py

@@ -0,0 +1,12 @@
+from fastapi import APIRouter, status
+
+router = APIRouter()
+
+
+@router.get("/health", status_code=status.HTTP_200_OK)
+async def health_check():
+    """
+    Health check endpoint for the application.
+    Returns 200 OK if the application is running properly.
+    """
+    return {"status": "ok"}

app/api/v1/endpoints/todos.py

@@ -0,0 +1,114 @@
+from typing import List
+
+from fastapi import APIRouter, Depends, HTTPException, Path, Query, status
+from sqlalchemy.orm import Session
+
+from app.crud import todo as todo_crud
+from app.db.session import get_db
+from app.schemas.todo import TodoCreate, TodoResponse, TodoUpdate
+
+router = APIRouter()
+
+
+@router.get("/", response_model=List[TodoResponse])
+async def get_todos(
+    skip: int = Query(0, ge=0),
+    limit: int = Query(100, ge=1, le=100),
+    db: Session = Depends(get_db),
+):
+    """
+    Get all todos.
+    
+    Args:
+        skip: Number of records to skip.
+        limit: Maximum number of records to return.
+        db: Database session.
+        
+    Returns:
+        List of todos.
+    """
+    todos = todo_crud.get_todos(db, skip=skip, limit=limit)
+    return todos
+
+
+@router.post("/", response_model=TodoResponse, status_code=status.HTTP_201_CREATED)
+async def create_todo(
+    todo: TodoCreate,
+    db: Session = Depends(get_db),
+):
+    """
+    Create a new todo.
+    
+    Args:
+        todo: Todo to create.
+        db: Database session.
+        
+    Returns:
+        Created todo.
+    """
+    return todo_crud.create_todo(db=db, todo=todo)
+
+
+@router.get("/{todo_id}", response_model=TodoResponse)
+async def get_todo(
+    todo_id: int = Path(..., gt=0),
+    db: Session = Depends(get_db),
+):
+    """
+    Get a specific todo by ID.
+    
+    Args:
+        todo_id: ID of the todo to get.
+        db: Database session.
+        
+    Returns:
+        Todo with the specified ID.
+    """
+    db_todo = todo_crud.get_todo(db, todo_id=todo_id)
+    if db_todo is None:
+        raise HTTPException(status_code=404, detail="Todo not found")
+    return db_todo
+
+
+@router.put("/{todo_id}", response_model=TodoResponse)
+async def update_todo(
+    todo: TodoUpdate,
+    todo_id: int = Path(..., gt=0),
+    db: Session = Depends(get_db),
+):
+    """
+    Update a todo.
+    
+    Args:
+        todo: Todo data to update.
+        todo_id: ID of the todo to update.
+        db: Database session.
+        
+    Returns:
+        Updated todo.
+    """
+    db_todo = todo_crud.update_todo(db, todo_id=todo_id, todo=todo)
+    if db_todo is None:
+        raise HTTPException(status_code=404, detail="Todo not found")
+    return db_todo
+
+
+@router.delete("/{todo_id}", status_code=status.HTTP_204_NO_CONTENT, response_model=None)
+async def delete_todo(
+    todo_id: int = Path(..., gt=0),
+    db: Session = Depends(get_db),
+):
+    """
+    Delete a todo.
+    
+    Args:
+        todo_id: ID of the todo to delete.
+        db: Database session.
+        
+    Returns:
+        204 No Content on success.
+    """
+    result = todo_crud.delete_todo(db, todo_id=todo_id)
+    if not result:
+        raise HTTPException(status_code=404, detail="Todo not found")
+    return None

app/core/app.py

@@ -0,0 +1,29 @@
+from fastapi import FastAPI
+from fastapi.middleware.cors import CORSMiddleware
+
+from app.api.routes import router as api_router
+from app.core.config import settings
+
+
+def create_app() -> FastAPI:
+    app = FastAPI(
+        title=settings.PROJECT_NAME,
+        description=settings.PROJECT_DESCRIPTION,
+        version=settings.PROJECT_VERSION,
+        docs_url="/docs",
+        redoc_url="/redoc",
+    )
+
+    # Set up CORS middleware
+    app.add_middleware(
+        CORSMiddleware,
+        allow_origins=settings.CORS_ORIGINS,
+        allow_credentials=True,
+        allow_methods=["*"],
+        allow_headers=["*"],
+    )
+
+    # Include routers
+    app.include_router(api_router)
+
+    return app

app/core/config.py

@@ -0,0 +1,24 @@
+from pathlib import Path
+from typing import List
+
+from pydantic_settings import BaseSettings
+
+
+class Settings(BaseSettings):
+    PROJECT_NAME: str = "Simple Todo App"
+    PROJECT_DESCRIPTION: str = "A simple todo application built with FastAPI and SQLite"
+    PROJECT_VERSION: str = "0.1.0"
+    
+    # CORS settings
+    CORS_ORIGINS: List[str] = ["*"]
+    
+    # Database settings
+    DB_DIR: Path = Path("/app") / "storage" / "db"
+    DB_FILE: Path = DB_DIR / "db.sqlite"
+    SQLALCHEMY_DATABASE_URL: str = f"sqlite:///{DB_FILE}"
+    
+    class Config:
+        case_sensitive = True
+
+
+settings = Settings()

app/crud/todo.py

@@ -0,0 +1,52 @@
+from typing import List, Optional
+
+from sqlalchemy.orm import Session
+
+from app.models.todo import Todo
+from app.schemas.todo import TodoCreate, TodoUpdate
+
+
+def get_todos(db: Session, skip: int = 0, limit: int = 100) -> List[Todo]:
+    """Get all todos."""
+    return db.query(Todo).offset(skip).limit(limit).all()
+
+
+def get_todo(db: Session, todo_id: int) -> Optional[Todo]:
+    """Get a specific todo by ID."""
+    return db.query(Todo).filter(Todo.id == todo_id).first()
+
+
+def create_todo(db: Session, todo: TodoCreate) -> Todo:
+    """Create a new todo."""
+    db_todo = Todo(**todo.model_dump())
+    db.add(db_todo)
+    db.commit()
+    db.refresh(db_todo)
+    return db_todo
+
+
+def update_todo(db: Session, todo_id: int, todo: TodoUpdate) -> Optional[Todo]:
+    """Update a todo."""
+    db_todo = get_todo(db, todo_id)
+    if not db_todo:
+        return None
+    
+    update_data = todo.model_dump(exclude_unset=True)
+    for key, value in update_data.items():
+        setattr(db_todo, key, value)
+    
+    db.add(db_todo)
+    db.commit()
+    db.refresh(db_todo)
+    return db_todo
+
+
+def delete_todo(db: Session, todo_id: int) -> bool:
+    """Delete a todo."""
+    db_todo = get_todo(db, todo_id)
+    if not db_todo:
+        return False
+    
+    db.delete(db_todo)
+    db.commit()
+    return True

app/db/base.py

@@ -0,0 +1,3 @@
+# Import all the models, so that Base has them before being imported by Alembic
+from app.db.base_class import Base  # noqa
+from app.models.todo import Todo  # noqa

app/db/base_class.py

@@ -0,0 +1,15 @@
+from typing import Any
+
+from sqlalchemy.ext.declarative import declared_attr
+from sqlalchemy.orm import DeclarativeBase
+
+
+class Base(DeclarativeBase):
+    """Base class for all SQLAlchemy database models."""
+    
+    id: Any
+    
+    @declared_attr.directive
+    def __tablename__(cls) -> str:
+        """Generate __tablename__ automatically from the class name."""
+        return cls.__name__.lower()

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 the DB directory if it doesn't exist
+settings.DB_DIR.mkdir(parents=True, exist_ok=True)
+
+# SQLite connection engine
+engine = create_engine(
+    settings.SQLALCHEMY_DATABASE_URL,
+    connect_args={"check_same_thread": False}
+)
+
+# Create a sessionmaker with a class
+SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
+
+
+def get_db():
+    """Dependency for getting a database session."""
+    db = SessionLocal()
+    try:
+        yield db
+    finally:
+        db.close()

app/models/__init__.py

@@ -0,0 +1 @@
+from app.models.todo import Todo  # noqa

app/models/todo.py

@@ -0,0 +1,24 @@
+from datetime import datetime
+from typing import Optional
+
+from sqlalchemy import Boolean, DateTime, Integer, String
+from sqlalchemy.orm import Mapped, mapped_column
+
+from app.db.base_class import Base
+
+
+class Todo(Base):
+    """Todo item model."""
+    
+    __tablename__ = "todos"
+    
+    id: Mapped[int] = mapped_column(Integer, primary_key=True, index=True)
+    title: Mapped[str] = mapped_column(String, index=True)
+    description: Mapped[Optional[str]] = mapped_column(String, nullable=True)
+    completed: Mapped[bool] = mapped_column(Boolean, default=False)
+    created_at: Mapped[datetime] = mapped_column(
+        DateTime, default=datetime.utcnow
+    )
+    updated_at: Mapped[datetime] = mapped_column(
+        DateTime, default=datetime.utcnow, onupdate=datetime.utcnow
+    )

app/schemas/__init__.py

@@ -0,0 +1 @@
+from app.schemas.todo import TodoBase, TodoCreate, TodoResponse, TodoUpdate  # noqa

app/schemas/todo.py

@@ -0,0 +1,38 @@
+from datetime import datetime
+from typing import Optional
+
+from pydantic import BaseModel, Field
+
+
+# Base schema for Todo
+class TodoBase(BaseModel):
+    """Base schema for Todo items."""
+    title: str = Field(..., min_length=1, max_length=100)
+    description: Optional[str] = Field(None, max_length=500)
+    completed: bool = False
+
+
+# Schema for creating a new Todo
+class TodoCreate(TodoBase):
+    """Schema for creating a new Todo."""
+    pass
+
+
+# Schema for updating a Todo
+class TodoUpdate(BaseModel):
+    """Schema for updating a Todo."""
+    title: Optional[str] = Field(None, min_length=1, max_length=100)
+    description: Optional[str] = Field(None, max_length=500)
+    completed: Optional[bool] = None
+
+
+# Schema for Todo in response
+class TodoResponse(TodoBase):
+    """Schema for Todo in response."""
+    id: int
+    created_at: datetime
+    updated_at: datetime
+
+    class Config:
+        """Pydantic config for Todo."""
+        from_attributes = True

main.py

@@ -0,0 +1,7 @@
+import uvicorn
+from app.core.app import create_app
+
+app = create_app()
+
+if __name__ == "__main__":
+    uvicorn.run("main:app", host="0.0.0.0", port=8000, reload=True)

migrations/env.py

@@ -0,0 +1,79 @@
+from logging.config import fileConfig
+
+from alembic import context
+from sqlalchemy import engine_from_config, pool
+
+# 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 myapp import mymodel
+# target_metadata = mymodel.Base.metadata
+from app.db.base import Base  # noqa
+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:
+        is_sqlite = connection.dialect.name == "sqlite"
+        context.configure(
+            connection=connection,
+            target_metadata=target_metadata,
+            render_as_batch=is_sqlite,  # Key configuration 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/7a8b9c0d1e2f_initial_migration.py

@@ -0,0 +1,40 @@
+"""Initial migration
+
+Revision ID: 7a8b9c0d1e2f
+Revises: 
+Create Date: 2023-10-30 00:00:00.000000
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = '7a8b9c0d1e2f'
+down_revision = None
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.create_table('todos',
+        sa.Column('id', sa.Integer(), nullable=False),
+        sa.Column('title', sa.String(), nullable=False),
+        sa.Column('description', sa.String(), nullable=True),
+        sa.Column('completed', sa.Boolean(), nullable=False, default=False),
+        sa.Column('created_at', sa.DateTime(), nullable=False),
+        sa.Column('updated_at', sa.DateTime(), nullable=False),
+        sa.PrimaryKeyConstraint('id')
+    )
+    op.create_index(op.f('ix_todos_id'), 'todos', ['id'], unique=False)
+    op.create_index(op.f('ix_todos_title'), 'todos', ['title'], unique=False)
+    # ### end Alembic commands ###
+
+
+def downgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.drop_index(op.f('ix_todos_title'), table_name='todos')
+    op.drop_index(op.f('ix_todos_id'), table_name='todos')
+    op.drop_table('todos')
+    # ### end Alembic commands ###

requirements.txt

@@ -0,0 +1,7 @@
+fastapi>=0.100.0
+uvicorn>=0.23.0
+pydantic>=2.0.0
+pydantic-settings>=2.0.0
+sqlalchemy>=2.0.0
+alembic>=1.11.0
+ruff>=0.1.0