Initial implementation of Todo API with FastAPI and SQLite

README.md

@@ -1,3 +1,86 @@
-# FastAPI Application
+# Simple Todo App
 
-This is a FastAPI application bootstrapped by BackendIM, the AI-powered backend generation platform.
+This is a simple Todo API application built with FastAPI and SQLite.
+
+## Features
+
+- Create, Read, Update, and Delete Todo items
+- Health check endpoint
+- Database migrations using Alembic
+- SQLite database for data storage
+
+## Project Structure
+
+```
+.
+├── alembic/             # Database migration files
+├── app/                 # Application package
+│   ├── database/        # Database configuration and session management
+│   ├── models/          # SQLAlchemy ORM models
+│   ├── routers/         # API route handlers
+│   └── schemas/         # Pydantic models for request/response validation
+├── alembic.ini          # Alembic configuration
+├── main.py              # Application entry point
+└── requirements.txt     # Project dependencies
+```
+
+## Installation
+
+1. Clone the repository:
+
+```bash
+git clone <repository-url>
+cd simpletodoapp
+```
+
+2. Create a virtual environment and activate it:
+
+```bash
+python -m venv venv
+source venv/bin/activate  # On Windows: venv\Scripts\activate
+```
+
+3. Install dependencies:
+
+```bash
+pip install -r requirements.txt
+```
+
+## Database Setup
+
+1. Run 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
+
+Once the application is running, you can access the Swagger UI documentation at:
+
+- http://localhost:8000/docs
+- http://localhost:8000/redoc
+
+## API Endpoints
+
+### Health Check
+
+- GET `/health`: Check the application health status
+
+### Todo Endpoints
+
+- GET `/todos`: List all todos
+- POST `/todos`: Create a new todo
+- GET `/todos/{todo_id}`: Get a specific todo by ID
+- PATCH `/todos/{todo_id}`: Update a specific todo
+- DELETE `/todos/{todo_id}`: Delete a specific todo

alembic.ini

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+# A generic, single database configuration.
+
+[alembic]
+# path to migration scripts
+script_location = alembic
+
+# 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 alembic/versions.  When using multiple version
+# directories, initial revisions must be specified with --version-path
+# version_locations = %(here)s/bar %(here)s/bat alembic/versions
+
+# the output encoding used when revision files
+# are written from script.py.mako
+# output_encoding = utf-8
+
+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

alembic/README

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+Generic single-database configuration with SQLite.

alembic/env.py

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+from logging.config import fileConfig
+
+from sqlalchemy import engine_from_config
+from sqlalchemy import pool
+
+from alembic import context
+
+# 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 app.database import Base
+from app.models.todo import Todo
+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:
+        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()

alembic/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():
+    ${upgrades if upgrades else "pass"}
+
+
+def downgrade():
+    ${downgrades if downgrades else "pass"}

alembic/versions/3b763f33c5e2_create_todos_table.py

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+"""create todos table
+
+Revision ID: 3b763f33c5e2
+Revises: 
+Create Date: 2023-07-20 16:20:45.978401
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = '3b763f33c5e2'
+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(timezone=True), server_default=sa.text('(CURRENT_TIMESTAMP)')),
+        sa.Column('updated_at', sa.DateTime(timezone=True), nullable=True),
+        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')

app/__init__.py

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+# This file is intentionally empty to make the directory a Python package

app/database/__init__.py

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+from pathlib import Path
+from sqlalchemy import create_engine
+from sqlalchemy.ext.declarative import declarative_base
+from sqlalchemy.orm import sessionmaker
+
+# Create database directory if it doesn't exist
+DB_DIR = Path("/app") / "storage" / "db"
+DB_DIR.mkdir(parents=True, exist_ok=True)
+
+# Database URL
+SQLALCHEMY_DATABASE_URL = f"sqlite:///{DB_DIR}/db.sqlite"
+
+# Create SQLAlchemy engine
+engine = create_engine(
+    SQLALCHEMY_DATABASE_URL,
+    connect_args={"check_same_thread": False}  # Needed for SQLite
+)
+
+# Create session factory
+SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
+
+# Create declarative base for models
+Base = declarative_base()
+
+# Database dependency
+def get_db():
+    db = SessionLocal()
+    try:
+        yield db
+    finally:
+        db.close()

app/models/__init__.py

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+# This file is intentionally empty to make the directory a Python package

app/models/todo.py

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+from sqlalchemy import Column, Integer, String, Boolean, DateTime
+from sqlalchemy.sql import func
+from app.database 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(timezone=True), server_default=func.now())
+    updated_at = Column(DateTime(timezone=True), onupdate=func.now())

app/routers/__init__.py

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+# This file is intentionally empty to make the directory a Python package

app/routers/health.py

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+from fastapi import APIRouter, Depends
+from sqlalchemy.orm import Session
+from app.database import get_db
+
+router = APIRouter(
+    tags=["health"],
+)
+
+@router.get("/health")
+def health_check(db: Session = Depends(get_db)):
+    """
+    Health check endpoint to verify API and database connectivity
+    """
+    # Try to execute a simple SQL query to verify database connection
+    try:
+        db.execute("SELECT 1")
+        db_status = "healthy"
+    except Exception:
+        db_status = "unhealthy"
+    
+    return {
+        "status": "ok" if db_status == "healthy" else "error",
+        "database": db_status
+    }

app/routers/todo.py

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+from fastapi import APIRouter, Depends, HTTPException, status
+from sqlalchemy.orm import Session
+from typing import List
+
+from app.database import get_db
+from app.models.todo import Todo
+from app.schemas.todo import TodoCreate, TodoResponse, TodoUpdate
+
+router = APIRouter(
+    prefix="/todos",
+    tags=["todos"],
+)
+
+@router.post("/", response_model=TodoResponse, status_code=status.HTTP_201_CREATED)
+def create_todo(todo: TodoCreate, db: Session = Depends(get_db)):
+    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
+
+@router.get("/", response_model=List[TodoResponse])
+def read_todos(skip: int = 0, limit: int = 100, db: Session = Depends(get_db)):
+    todos = db.query(Todo).offset(skip).limit(limit).all()
+    return todos
+
+@router.get("/{todo_id}", response_model=TodoResponse)
+def read_todo(todo_id: int, db: Session = Depends(get_db)):
+    db_todo = db.query(Todo).filter(Todo.id == todo_id).first()
+    if db_todo is None:
+        raise HTTPException(status_code=404, detail="Todo not found")
+    return db_todo
+
+@router.patch("/{todo_id}", response_model=TodoResponse)
+def update_todo(todo_id: int, todo: TodoUpdate, db: Session = Depends(get_db)):
+    db_todo = db.query(Todo).filter(Todo.id == todo_id).first()
+    if db_todo is None:
+        raise HTTPException(status_code=404, detail="Todo not found")
+    
+    update_data = todo.model_dump(exclude_unset=True)
+    for key, value in update_data.items():
+        setattr(db_todo, key, value)
+    
+    db.commit()
+    db.refresh(db_todo)
+    return db_todo
+
+@router.delete("/{todo_id}", status_code=status.HTTP_204_NO_CONTENT)
+def delete_todo(todo_id: int, db: Session = Depends(get_db)):
+    db_todo = db.query(Todo).filter(Todo.id == todo_id).first()
+    if db_todo is None:
+        raise HTTPException(status_code=404, detail="Todo not found")
+    
+    db.delete(db_todo)
+    db.commit()
+    return None

app/schemas/__init__.py

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+# This file is intentionally empty to make the directory a Python package

app/schemas/todo.py

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+from pydantic import BaseModel
+from datetime import datetime
+from typing import Optional
+
+# Base Schema for Todo items
+class TodoBase(BaseModel):
+    title: str
+    description: Optional[str] = None
+    completed: bool = False
+
+# Schema for Todo creation
+class TodoCreate(TodoBase):
+    pass
+
+# Schema for Todo update
+class TodoUpdate(BaseModel):
+    title: Optional[str] = None
+    description: Optional[str] = None
+    completed: Optional[bool] = None
+
+# Schema for Todo response
+class TodoResponse(TodoBase):
+    id: int
+    created_at: datetime
+    updated_at: Optional[datetime] = None
+
+    class Config:
+        from_attributes = True

main.py

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+from fastapi import FastAPI
+from fastapi.middleware.cors import CORSMiddleware
+from contextlib import asynccontextmanager
+from pathlib import Path
+
+from app.routers import todo, health
+from app.database import engine, Base
+
+# Create the database tables
+@asynccontextmanager
+async def lifespan(app: FastAPI):
+    Base.metadata.create_all(bind=engine)
+    yield
+
+# Initialize FastAPI app
+app = FastAPI(
+    title="Simple Todo API",
+    description="A simple Todo API built with FastAPI and SQLite",
+    version="0.1.0",
+    lifespan=lifespan
+)
+
+# Add CORS middleware
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=["*"],  # For development, in production specify the allowed origins
+    allow_credentials=True,
+    allow_methods=["*"],
+    allow_headers=["*"],
+)
+
+# Include routers
+app.include_router(health.router)
+app.include_router(todo.router)

pyproject.toml

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+[tool.ruff]
+line-length = 88
+target-version = "py310"
+select = ["E", "F", "I", "W", "N", "UP", "B", "C90", "YTT", "ANN", "ASYNC", "A", "COM", "C4", "EM", "FA", "ISC", "ICN", "G", "INP", "PIE", "T20", "PT", "Q", "RSE", "RET", "SLOT", "SIM", "TID", "TCH", "INT", "ARG", "ERA"]
+ignore = ["E501", "B008", "ANN101"]
+
+[tool.ruff.isort]
+known-third-party = ["fastapi", "pydantic", "sqlalchemy", "starlette"]

requirements.txt

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+fastapi==0.101.0
+uvicorn==0.23.2
+sqlalchemy==2.0.19
+alembic==1.11.1
+pydantic==2.1.1
+pydantic-settings==2.0.2
+python-dotenv==1.0.0
+ruff==0.0.282