Create simple todo app with FastAPI and SQLite

README.md

@@ -1,3 +1,109 @@
-# 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
+
+- Create, read, update, and delete todo items
+- RESTful API with JSON responses
+- SQLite database with SQLAlchemy ORM
+- Alembic for database migrations
+- API documentation with Swagger UI and ReDoc
+
+## Project Structure
+
+```
+.
+├── alembic.ini
+├── app
+│   ├── api
+│   │   ├── endpoints
+│   │   │   ├── health.py
+│   │   │   └── todos.py
+│   │   └── router.py
+│   ├── core
+│   │   └── config.py
+│   ├── database
+│   │   ├── base.py
+│   │   └── deps.py
+│   ├── models
+│   │   └── todo.py
+│   ├── schemas
+│   │   └── todo.py
+│   └── services
+│       └── todo_service.py
+├── main.py
+├── migrations
+│   ├── env.py
+│   ├── README
+│   ├── script.py.mako
+│   └── versions
+│       └── 001_create_todos_table.py
+└── requirements.txt
+```
+
+## Installation
+
+1. Clone the repository:
+
+```bash
+git clone <repository-url>
+cd simpletodoapp
+```
+
+2. Create a virtual environment and install dependencies:
+
+```bash
+python -m venv venv
+source venv/bin/activate  # On Windows, use `venv\\Scripts\\activate`
+pip install -r requirements.txt
+```
+
+3. Run the application:
+
+```bash
+uvicorn main:app --reload
+```
+
+The application will be available at http://localhost:8000.
+
+## API Documentation
+
+API documentation is available at:
+
+- Swagger UI: http://localhost:8000/docs
+- ReDoc: http://localhost:8000/redoc
+
+## API Endpoints
+
+### Health Check
+
+- `GET /health` - Check API health status
+
+### Todos
+
+- `GET /api/v1/todos` - Get all todos (with pagination)
+- `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
+
+## Database Migrations
+
+The application uses Alembic for database migrations:
+
+1. Run migrations:
+
+```bash
+alembic upgrade head
+```
+
+2. Create a new migration:
+
+```bash
+alembic revision -m "your migration message"
+```
+
+## License
+
+MIT

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
+
+# SQLite URL - using 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
+
+# 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

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+# Initialize the app package

app/api/__init__.py

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+# Initialize the api package

app/api/deps.py

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+# Placeholder for API-specific dependencies

app/api/endpoints/__init__.py

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+# Initialize the endpoints package

app/api/endpoints/health.py

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+from typing import Dict
+from fastapi import APIRouter
+
+router = APIRouter()
+
+
+@router.get("/", response_model=Dict[str, str])
+def health_check() -> Dict[str, str]:
+    """
+    Health check endpoint.
+    Returns a successful response if the API is running.
+    """
+    return {"status": "ok"}

app/api/endpoints/todos.py

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+from typing import List, Any
+from fastapi import APIRouter, Depends, HTTPException, status
+from sqlalchemy.orm import Session
+
+from app.database.deps import get_db
+from app.schemas.todo import TodoCreate, TodoUpdate, TodoResponse
+from app.services import todo_service
+
+router = APIRouter()
+
+
+@router.get("/", response_model=List[TodoResponse])
+def read_todos(
+    skip: int = 0, 
+    limit: int = 100, 
+    db: Session = Depends(get_db)
+) -> Any:
+    """
+    Retrieve todos with pagination.
+    """
+    todos = todo_service.get_todos(db, skip=skip, limit=limit)
+    return todos
+
+
+@router.post("/", response_model=TodoResponse, status_code=status.HTTP_201_CREATED)
+def create_todo(
+    todo_in: TodoCreate, 
+    db: Session = Depends(get_db)
+) -> Any:
+    """
+    Create new todo.
+    """
+    todo = todo_service.create_todo(db=db, todo=todo_in)
+    return todo
+
+
+@router.get("/{todo_id}", response_model=TodoResponse)
+def read_todo(
+    todo_id: int, 
+    db: Session = Depends(get_db)
+) -> Any:
+    """
+    Get todo by ID.
+    """
+    todo = todo_service.get_todo(db=db, todo_id=todo_id)
+    if todo is None:
+        raise HTTPException(status_code=404, detail="Todo not found")
+    return todo
+
+
+@router.put("/{todo_id}", response_model=TodoResponse)
+def update_todo(
+    todo_id: int, 
+    todo_in: TodoUpdate, 
+    db: Session = Depends(get_db)
+) -> Any:
+    """
+    Update a todo.
+    """
+    todo = todo_service.update_todo(db=db, todo_id=todo_id, todo_update=todo_in)
+    if todo is None:
+        raise HTTPException(status_code=404, detail="Todo not found")
+    return todo
+
+
+@router.delete("/{todo_id}", status_code=status.HTTP_204_NO_CONTENT, response_model=None)
+def delete_todo(
+    todo_id: int, 
+    db: Session = Depends(get_db)
+) -> Any:
+    """
+    Delete a todo.
+    """
+    success = todo_service.delete_todo(db=db, todo_id=todo_id)
+    if not success:
+        raise HTTPException(status_code=404, detail="Todo not found")
+    return None

app/api/router.py

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+from fastapi import APIRouter
+
+from app.api.endpoints import todos, health
+
+api_router = APIRouter()
+api_router.include_router(todos.router, prefix="/todos", tags=["todos"])
+api_router.include_router(health.router, prefix="/health", tags=["health"])

app/core/config.py

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+from pathlib import Path
+from pydantic_settings import BaseSettings
+
+class Settings(BaseSettings):
+    API_V1_STR: str = "/api/v1"
+    PROJECT_NAME: str = "Todo App"
+    
+    # CORS Settings
+    CORS_ORIGINS: list[str] = ["*"]
+    
+    # Database
+    DB_DIR: Path = Path("/app") / "storage" / "db"
+    
+    class Config:
+        env_file = ".env"
+        env_file_encoding = "utf-8"
+        case_sensitive = True
+
+settings = Settings()
+
+# Ensure DB directory exists
+settings.DB_DIR.mkdir(parents=True, exist_ok=True)

app/database/__init__.py

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+# Initialize the database package

app/database/base.py

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+from sqlalchemy import create_engine
+from sqlalchemy.ext.declarative import declarative_base
+from sqlalchemy.orm import sessionmaker
+
+from app.core.config import settings
+
+SQLALCHEMY_DATABASE_URL = f"sqlite:///{settings.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()

app/database/deps.py

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+from typing import Generator
+
+from sqlalchemy.orm import Session
+
+from app.database.base import SessionLocal
+
+def get_db() -> Generator[Session, None, None]:
+    """
+    Dependency for getting database session.
+    """
+    db = SessionLocal()
+    try:
+        yield db
+    finally:
+        db.close()

app/models/__init__.py

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+from app.models.todo import Todo
+
+# Add all models here for easier imports
+__all__ = ["Todo"]

app/models/todo.py

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+from datetime import datetime
+from sqlalchemy import Column, Integer, String, Boolean, DateTime
+
+from app.database.base import Base
+
+class Todo(Base):
+    __tablename__ = "todos"
+
+    id = Column(Integer, primary_key=True, index=True)
+    title = Column(String, index=True)
+    description = Column(String, nullable=True)
+    completed = Column(Boolean, default=False)
+    
+    created_at = Column(DateTime, default=datetime.utcnow)
+    updated_at = Column(DateTime, default=datetime.utcnow, onupdate=datetime.utcnow)

app/schemas/__init__.py

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+from app.schemas.todo import TodoBase, TodoCreate, TodoUpdate, TodoResponse
+
+# Add all schema classes here for easier imports
+__all__ = ["TodoBase", "TodoCreate", "TodoUpdate", "TodoResponse"]

app/schemas/todo.py

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+from datetime import datetime
+from typing import Optional
+
+from pydantic import BaseModel
+
+# Base Todo Schema (shared properties)
+class TodoBase(BaseModel):
+    title: str
+    description: Optional[str] = None
+    completed: bool = False
+
+# Schema for creating a Todo
+class TodoCreate(TodoBase):
+    pass
+
+# Schema for updating a Todo
+class TodoUpdate(BaseModel):
+    title: Optional[str] = None
+    description: Optional[str] = None
+    completed: Optional[bool] = None
+
+# Schema for reading a Todo (returned to clients)
+class TodoResponse(TodoBase):
+    id: int
+    created_at: datetime
+    updated_at: datetime
+
+    class Config:
+        from_attributes = True

app/services/__init__.py

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+# Initialize the services package

app/services/todo_service.py

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+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_todo(db: Session, todo_id: int) -> Optional[Todo]:
+    """
+    Get a single todo by ID
+    """
+    return db.query(Todo).filter(Todo.id == todo_id).first()
+
+
+def get_todos(db: Session, skip: int = 0, limit: int = 100) -> List[Todo]:
+    """
+    Get multiple todos with pagination
+    """
+    return db.query(Todo).offset(skip).limit(limit).all()
+
+
+def create_todo(db: Session, todo: TodoCreate) -> Todo:
+    """
+    Create a new todo
+    """
+    db_todo = Todo(
+        title=todo.title,
+        description=todo.description,
+        completed=todo.completed
+    )
+    db.add(db_todo)
+    db.commit()
+    db.refresh(db_todo)
+    return db_todo
+
+
+def update_todo(db: Session, todo_id: int, todo_update: TodoUpdate) -> Optional[Todo]:
+    """
+    Update an existing todo
+    """
+    db_todo = get_todo(db, todo_id)
+    if db_todo is None:
+        return None
+
+    update_data = todo_update.dict(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 by ID
+    """
+    db_todo = get_todo(db, todo_id)
+    if db_todo is None:
+        return False
+
+    db.delete(db_todo)
+    db.commit()
+    return True

main.py

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+import uvicorn
+from fastapi import FastAPI
+from fastapi.middleware.cors import CORSMiddleware
+
+from app.core.config import settings
+from app.api.router import api_router
+
+app = FastAPI(
+    title=settings.PROJECT_NAME,
+    openapi_url=f"{settings.API_V1_STR}/openapi.json"
+)
+
+# Set up CORS middleware
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=settings.CORS_ORIGINS,
+    allow_credentials=True,
+    allow_methods=["*"],
+    allow_headers=["*"],
+)
+
+# Include API router
+app.include_router(api_router, prefix=settings.API_V1_STR)
+
+# Health check at root level
+@app.get("/health")
+def health():
+    """
+    Root-level health check endpoint.
+    """
+    return {"status": "ok"}
+
+if __name__ == "__main__":
+    uvicorn.run("main:app", host="0.0.0.0", port=8000, reload=True)

migrations/README

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+Generic single-database configuration with SQLite.

migrations/env.py

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+from logging.config import fileConfig
+
+from alembic import context
+from sqlalchemy import engine_from_config, pool
+
+# Import models to include them in metadata
+# This import is needed for Alembic to detect model changes
+from app.models import Todo  # noqa: F401
+from app.database.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"},
+    )
+
+    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,  # 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

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+"""${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/001_create_todos_table.py

@@ -0,0 +1,38 @@
+"""create todos table
+
+Revision ID: 001
+Revises: 
+Create Date: 2023-10-22
+
+"""
+from alembic import op
+import sqlalchemy as sa
+from datetime import datetime
+
+
+# revision identifiers, used by Alembic.
+revision = '001'
+down_revision = None
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    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(), default=False),
+        sa.Column('created_at', sa.DateTime(), default=datetime.utcnow),
+        sa.Column('updated_at', sa.DateTime(), default=datetime.utcnow, onupdate=datetime.utcnow),
+        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)
+
+
+def downgrade() -> None:
+    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')

requirements.txt

@@ -0,0 +1,8 @@
+fastapi>=0.104.0
+uvicorn>=0.24.0
+sqlalchemy>=2.0.0
+alembic>=1.12.0
+pydantic>=2.4.0
+pydantic-settings>=2.0.0
+python-dotenv>=1.0.0
+ruff>=0.1.0