Implement simple todo app with FastAPI and SQLite

README.md

@@ -1,3 +1,93 @@
-# FastAPI Application
+# Simple Todo App
 
-This is a FastAPI application bootstrapped by BackendIM, the AI-powered backend generation platform.
+A simple Todo application backend built with FastAPI and SQLite.
+
+## Features
+
+- CRUD operations for Todo items
+- SQLite database with SQLAlchemy ORM
+- Alembic for database migrations
+- Health check endpoint
+- OpenAPI documentation
+
+## Prerequisites
+
+- Python 3.8+
+- pip
+
+## Installation
+
+1. Clone the repository:
+
+```bash
+git clone <repository-url>
+cd simpletodoapp-t3firn
+```
+
+2. Install the dependencies:
+
+```bash
+pip install -r requirements.txt
+```
+
+3. Run database migrations:
+
+```bash
+alembic upgrade head
+```
+
+## Usage
+
+Start the application with:
+
+```bash
+uvicorn main:app --reload
+```
+
+The API will be available at http://localhost:8000
+
+## API Documentation
+
+OpenAPI documentation is available at:
+
+- Swagger UI: http://localhost:8000/docs
+- ReDoc: http://localhost:8000/redoc
+
+## API Endpoints
+
+| Endpoint | Method | Description |
+|----------|--------|-------------|
+| `/api/v1/todos` | GET | List all todos |
+| `/api/v1/todos/{id}` | GET | Get a specific todo by ID |
+| `/api/v1/todos` | POST | Create a new todo |
+| `/api/v1/todos/{id}` | PUT | Update an existing todo |
+| `/api/v1/todos/{id}` | DELETE | Delete a todo |
+| `/health` | GET | Health check endpoint |
+
+## Todo Item Structure
+
+```json
+{
+  "id": 1,
+  "title": "Task title",
+  "description": "Task description",
+  "completed": false,
+  "created_at": "2023-12-01T12:00:00",
+  "updated_at": "2023-12-01T12:00:00"
+}
+```
+
+## Database Schema
+
+The application uses a SQLite database with the following schema:
+
+### Todos Table
+
+| Column | Type | Constraints |
+|--------|------|-------------|
+| id | Integer | Primary Key, Auto Increment |
+| title | String | Not Null, Indexed |
+| description | String | Nullable |
+| completed | Boolean | Default: False |
+| created_at | DateTime | Not Null |
+| updated_at | DateTime | Not Null |

alembic.ini

@@ -0,0 +1,85 @@
+# 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 example
+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/api/routes/__init__.py

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

app/api/routes/todos.py

@@ -0,0 +1,92 @@
+from typing import Any, List
+
+from fastapi import APIRouter, Depends, HTTPException, status
+from sqlalchemy.orm import Session
+
+from app import crud, schemas
+from app.db.session import get_db
+
+router = APIRouter()
+
+
+@router.get("/", response_model=List[schemas.Todo])
+def read_todos(
+    db: Session = Depends(get_db),
+    skip: int = 0,
+    limit: int = 100,
+) -> Any:
+    """
+    Retrieve todos.
+    """
+    todos = crud.todo.get_multi(db, skip=skip, limit=limit)
+    return todos
+
+
+@router.post("/", response_model=schemas.Todo, status_code=status.HTTP_201_CREATED)
+def create_todo(
+    *,
+    db: Session = Depends(get_db),
+    todo_in: schemas.TodoCreate,
+) -> Any:
+    """
+    Create new todo.
+    """
+    todo = crud.todo.create(db=db, obj_in=todo_in)
+    return todo
+
+
+@router.get("/{id}", response_model=schemas.Todo)
+def read_todo(
+    *,
+    db: Session = Depends(get_db),
+    id: int,
+) -> Any:
+    """
+    Get todo by ID.
+    """
+    todo = crud.todo.get(db=db, id=id)
+    if not todo:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="Todo not found",
+        )
+    return todo
+
+
+@router.put("/{id}", response_model=schemas.Todo)
+def update_todo(
+    *,
+    db: Session = Depends(get_db),
+    id: int,
+    todo_in: schemas.TodoUpdate,
+) -> Any:
+    """
+    Update a todo.
+    """
+    todo = crud.todo.get(db=db, id=id)
+    if not todo:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="Todo not found",
+        )
+    todo = crud.todo.update(db=db, db_obj=todo, obj_in=todo_in)
+    return todo
+
+
+@router.delete("/{id}", status_code=status.HTTP_204_NO_CONTENT, response_model=None)
+def delete_todo(
+    *,
+    db: Session = Depends(get_db),
+    id: int,
+) -> Any:
+    """
+    Delete a todo.
+    """
+    todo = crud.todo.get(db=db, id=id)
+    if not todo:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="Todo not found",
+        )
+    crud.todo.remove(db=db, id=id)
+    return None

app/core/config.py

@@ -0,0 +1,31 @@
+from pathlib import Path
+from typing import Any, List
+
+from pydantic import AnyHttpUrl, validator
+from pydantic_settings import BaseSettings
+
+
+class Settings(BaseSettings):
+    API_V1_STR: str = "/api/v1"
+    PROJECT_NAME: str = "Todo App API"
+    
+    # CORS Configuration
+    BACKEND_CORS_ORIGINS: List[AnyHttpUrl] = []
+
+    @validator("BACKEND_CORS_ORIGINS", pre=True)
+    def assemble_cors_origins(cls, v: Any) -> 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)
+    
+    # Database
+    DB_DIR: Path = Path("/app") / "storage" / "db"
+    
+    class Config:
+        case_sensitive = True
+        env_file = ".env"
+
+
+settings = Settings()

app/crud/__init__.py

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+from app.crud.todo import todo
+
+__all__ = ["todo"]

app/crud/base.py

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+from typing import Any, Dict, Generic, List, Optional, Type, TypeVar, Union
+
+from fastapi.encoders import jsonable_encoder
+from pydantic import BaseModel
+from sqlalchemy.orm import Session
+
+from app.db.session import Base
+
+ModelType = TypeVar("ModelType", bound=Base)
+CreateSchemaType = TypeVar("CreateSchemaType", bound=BaseModel)
+UpdateSchemaType = TypeVar("UpdateSchemaType", bound=BaseModel)
+
+
+class CRUDBase(Generic[ModelType, CreateSchemaType, UpdateSchemaType]):
+    def __init__(self, model: Type[ModelType]):
+        """
+        CRUD object with default methods to Create, Read, Update, Delete (CRUD).
+
+        **Parameters**
+
+        * `model`: A SQLAlchemy model class
+        * `schema`: A Pydantic model (schema) class
+        """
+        self.model = model
+
+    def get(self, db: Session, id: Any) -> Optional[ModelType]:
+        return db.query(self.model).filter(self.model.id == id).first()
+
+    def get_multi(
+        self, db: Session, *, skip: int = 0, limit: int = 100
+    ) -> List[ModelType]:
+        return db.query(self.model).offset(skip).limit(limit).all()
+
+    def create(self, db: Session, *, obj_in: CreateSchemaType) -> ModelType:
+        obj_in_data = jsonable_encoder(obj_in)
+        db_obj = self.model(**obj_in_data)
+        db.add(db_obj)
+        db.commit()
+        db.refresh(db_obj)
+        return db_obj
+
+    def update(
+        self,
+        db: Session,
+        *,
+        db_obj: ModelType,
+        obj_in: Union[UpdateSchemaType, Dict[str, Any]]
+    ) -> ModelType:
+        obj_data = jsonable_encoder(db_obj)
+        if isinstance(obj_in, dict):
+            update_data = obj_in
+        else:
+            update_data = obj_in.model_dump(exclude_unset=True)
+        for field in obj_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(self, db: Session, *, id: int) -> ModelType:
+        obj = db.query(self.model).get(id)
+        db.delete(obj)
+        db.commit()
+        return obj

app/crud/todo.py

@@ -0,0 +1,10 @@
+from app.crud.base import CRUDBase
+from app.models.todo import Todo
+from app.schemas.todo import TodoCreate, TodoUpdate
+
+
+class CRUDTodo(CRUDBase[Todo, TodoCreate, TodoUpdate]):
+    pass
+
+
+todo = CRUDTodo(Todo)

app/db/session.py

@@ -0,0 +1,27 @@
+from sqlalchemy import create_engine
+from sqlalchemy.ext.declarative import declarative_base
+from sqlalchemy.orm import sessionmaker
+
+from app.core.config import settings
+
+# Ensure the database directory exists
+settings.DB_DIR.mkdir(parents=True, exist_ok=True)
+
+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()
+
+
+# Dependency
+def get_db():
+    db = SessionLocal()
+    try:
+        yield db
+    finally:
+        db.close()

app/models/__init__.py

@@ -0,0 +1,3 @@
+from app.models.todo import Todo
+
+__all__ = ["Todo"]

app/models/todo.py

@@ -0,0 +1,15 @@
+from datetime import datetime
+from sqlalchemy import Column, Integer, String, Boolean, DateTime
+
+from app.db.session 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

@@ -0,0 +1,3 @@
+from app.schemas.todo import Todo, TodoCreate, TodoUpdate
+
+__all__ = ["Todo", "TodoCreate", "TodoUpdate"]

app/schemas/todo.py

@@ -0,0 +1,37 @@
+from datetime import datetime
+from typing import Optional
+
+from pydantic import BaseModel
+
+
+# Shared properties
+class TodoBase(BaseModel):
+    title: str
+    description: Optional[str] = None
+    completed: bool = False
+
+
+# Properties to receive on item creation
+class TodoCreate(TodoBase):
+    pass
+
+
+# Properties to receive on item update
+class TodoUpdate(TodoBase):
+    title: Optional[str] = None
+    completed: Optional[bool] = None
+
+
+# Properties shared by models stored in DB
+class TodoInDBBase(TodoBase):
+    id: int
+    created_at: datetime
+    updated_at: datetime
+
+    class Config:
+        from_attributes = True
+
+
+# Properties to return to client
+class Todo(TodoInDBBase):
+    pass

main.py

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+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
+
+app = FastAPI(
+    title=settings.PROJECT_NAME,
+    openapi_url=f"{settings.API_V1_STR}/openapi.json",
+)
+
+# Set all CORS enabled origins
+if settings.BACKEND_CORS_ORIGINS:
+    app.add_middleware(
+        CORSMiddleware,
+        allow_origins=[str(origin) for origin in settings.BACKEND_CORS_ORIGINS],
+        allow_credentials=True,
+        allow_methods=["*"],
+        allow_headers=["*"],
+    )
+
+app.include_router(api_router, prefix=settings.API_V1_STR)
+
+
+@app.get("/health", tags=["health"])
+async def health_check():
+    """Health check endpoint for the application."""
+    return {"status": "ok"}
+
+
+if __name__ == "__main__":
+    import uvicorn
+    
+    uvicorn.run("main:app", host="0.0.0.0", port=8000, reload=True)

migrations/env.py

@@ -0,0 +1,84 @@
+from logging.config import fileConfig
+
+from sqlalchemy import engine_from_config
+from sqlalchemy import pool
+
+from alembic import context
+
+from app.db.session import Base
+from app.models import todo  # noqa: F401, must import all models to include them in metadata
+
+# 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
+# from myapp import mymodel
+# target_metadata = mymodel.Base.metadata
+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/001_create_todos_table.py

@@ -0,0 +1,37 @@
+"""Create todos table
+
+Revision ID: 001
+Revises: 
+Create Date: 2023-12-01
+
+"""
+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(
+        '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)
+
+
+def downgrade():
+    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>=0.104.1
+uvicorn>=0.24.0
+pydantic>=2.5.2
+sqlalchemy>=2.0.23
+alembic>=1.12.1
+ruff>=0.1.6
+python-dotenv>=1.0.0
+pydantic-settings>=2.1.0