Implement Todo API with FastAPI and SQLite

README.md

@@ -1,3 +1,96 @@
-# FastAPI Application
+# Todo App API
 
-This is a FastAPI application bootstrapped by BackendIM, the AI-powered backend generation platform.
+This is a simple Todo application backend built with FastAPI and SQLite.
+
+## Features
+
+- Create, read, update, and delete Todo items
+- Filter Todos by completion status
+- RESTful API with proper status codes
+- SQLite database with SQLAlchemy ORM
+- Database migrations with Alembic
+- Input validation with Pydantic
+- CORS support
+- Health check endpoint
+
+## Requirements
+
+- Python 3.8+
+- FastAPI
+- SQLAlchemy
+- Alembic
+- Uvicorn
+- Pydantic
+- Ruff (for linting)
+
+## Installation
+
+1. Clone the repository:
+```bash
+git clone <repository-url>
+cd todoappbackend-uspc3m
+```
+
+2. Install dependencies:
+```bash
+pip install -r requirements.txt
+```
+
+## Configuration
+
+The application uses environment variables for configuration. You can create a `.env` file in the root directory with the following settings:
+
+```
+PROJECT_NAME=Todo App API
+```
+
+## Database Setup
+
+The application uses SQLite by default. The database file will be created at `/app/storage/db/db.sqlite`.
+
+To initialize the database:
+
+```bash
+# Run the database migrations
+alembic upgrade head
+```
+
+## Running the Application
+
+```bash
+# Development server
+uvicorn main:app --reload
+
+# Production server
+uvicorn main:app --host 0.0.0.0 --port 8000
+```
+
+## API Documentation
+
+Once the application is running, you can access the API documentation at:
+
+- Swagger UI: http://localhost:8000/docs
+- ReDoc: http://localhost:8000/redoc
+
+## API Endpoints
+
+- `GET /api/v1/todos`: Get 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
+- `GET /health`: Health check endpoint
+
+## Development
+
+### Linting
+
+```bash
+ruff check .
+```
+
+### Fix linting issues
+
+```bash
+ruff check --fix .
+```

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
+
+# Use absolute path for SQLite URL
+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/endpoints/todos.py

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+from typing import List, Optional
+
+from fastapi import APIRouter, Depends, HTTPException, status
+from sqlalchemy.orm import Session
+
+from app.db.session import get_db
+from app.models.todo import Todo
+from app.schemas.todo import Todo as TodoSchema
+from app.schemas.todo import TodoCreate, TodoUpdate
+
+router = APIRouter()
+
+
+@router.get("/", response_model=List[TodoSchema])
+def read_todos(
+    skip: int = 0,
+    limit: int = 100,
+    completed: Optional[bool] = None,
+    db: Session = Depends(get_db),
+):
+    """
+    Retrieve todos.
+    """
+    query = db.query(Todo)
+
+    if completed is not None:
+        query = query.filter(Todo.completed == completed)
+
+    todos = query.offset(skip).limit(limit).all()
+    return todos
+
+
+@router.post("/", response_model=TodoSchema, status_code=status.HTTP_201_CREATED)
+def create_todo(
+    todo_in: TodoCreate,
+    db: Session = Depends(get_db),
+):
+    """
+    Create new todo.
+    """
+    todo = Todo(
+        title=todo_in.title,
+        description=todo_in.description,
+        completed=todo_in.completed,
+    )
+    db.add(todo)
+    db.commit()
+    db.refresh(todo)
+    return todo
+
+
+@router.get("/{todo_id}", response_model=TodoSchema)
+def read_todo(
+    todo_id: int,
+    db: Session = Depends(get_db),
+):
+    """
+    Get todo by ID.
+    """
+    todo = db.query(Todo).filter(Todo.id == todo_id).first()
+    if not todo:
+        raise HTTPException(status_code=404, detail="Todo not found")
+    return todo
+
+
+@router.put("/{todo_id}", response_model=TodoSchema)
+def update_todo(
+    todo_id: int,
+    todo_in: TodoUpdate,
+    db: Session = Depends(get_db),
+):
+    """
+    Update a todo.
+    """
+    todo = db.query(Todo).filter(Todo.id == todo_id).first()
+    if not todo:
+        raise HTTPException(status_code=404, detail="Todo not found")
+
+    update_data = todo_in.dict(exclude_unset=True)
+    for field, value in update_data.items():
+        setattr(todo, field, value)
+
+    db.add(todo)
+    db.commit()
+    db.refresh(todo)
+    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),
+):
+    """
+    Delete a todo.
+    """
+    todo = db.query(Todo).filter(Todo.id == todo_id).first()
+    if not todo:
+        raise HTTPException(status_code=404, detail="Todo not found")
+
+    db.delete(todo)
+    db.commit()
+    return None

app/api/routes.py

@@ -0,0 +1,8 @@
+from fastapi import APIRouter
+
+from app.api.endpoints import todos
+from app.core.config import settings
+
+api_router = APIRouter(prefix=settings.API_V1_STR)
+
+api_router.include_router(todos.router, prefix="/todos", tags=["todos"])

app/core/config.py

@@ -0,0 +1,32 @@
+from pathlib import Path
+from typing import Any, Dict, Optional
+
+from pydantic import BaseSettings, validator
+
+
+class Settings(BaseSettings):
+    PROJECT_NAME: str = "Todo App API"
+    API_V1_STR: str = "/api/v1"
+
+    # Database
+    DB_DIR: Path = Path("/app") / "storage" / "db"
+    SQLALCHEMY_DATABASE_URL: Optional[str] = None
+
+    @validator("SQLALCHEMY_DATABASE_URL", pre=True)
+    def assemble_db_url(cls, v: Optional[str], values: Dict[str, Any]) -> str:
+        if v:
+            return v
+
+        db_dir = values.get("DB_DIR")
+        if db_dir:
+            db_dir.mkdir(parents=True, exist_ok=True)
+            return f"sqlite:///{db_dir}/db.sqlite"
+
+        return "sqlite:///./db.sqlite"
+
+    class Config:
+        env_file = ".env"
+        case_sensitive = True
+
+
+settings = Settings()

app/db/base.py

@@ -0,0 +1,3 @@
+from sqlalchemy.ext.declarative import declarative_base
+
+Base = declarative_base()

app/db/base_class.py

@@ -0,0 +1,2 @@
+from app.db.base import Base  # noqa
+from app.models.todo import Todo  # noqa

app/db/session.py

@@ -0,0 +1,19 @@
+from sqlalchemy import create_engine
+from sqlalchemy.orm import sessionmaker
+
+from app.core.config import settings
+
+engine = create_engine(
+    settings.SQLALCHEMY_DATABASE_URL,
+    connect_args={"check_same_thread": False}  # Needed for SQLite
+)
+
+SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
+
+
+def get_db():
+    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 +1,16 @@
+from datetime import datetime
+
+from sqlalchemy import Boolean, Column, DateTime, Integer, String, Text
+
+from app.db.base import Base
+
+
+class Todo(Base):
+    __tablename__ = "todos"
+
+    id = Column(Integer, primary_key=True, index=True)
+    title = Column(String(255), nullable=False)
+    description = Column(Text, 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/todo.py

@@ -0,0 +1,38 @@
+from datetime import datetime
+from typing import Optional
+
+from pydantic import BaseModel, Field
+
+
+# Shared properties
+class TodoBase(BaseModel):
+    title: str = Field(..., min_length=1, max_length=255)
+    description: Optional[str] = None
+    completed: bool = False
+
+
+# Properties to receive on todo creation
+class TodoCreate(TodoBase):
+    pass
+
+
+# Properties to receive on todo update
+class TodoUpdate(BaseModel):
+    title: Optional[str] = Field(None, min_length=1, max_length=255)
+    description: 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:
+        orm_mode = True
+
+
+# Properties to return to client
+class Todo(TodoInDBBase):
+    pass

main.py

@@ -0,0 +1,43 @@
+import uvicorn
+from fastapi import FastAPI
+from fastapi.middleware.cors import CORSMiddleware
+
+from app.api.routes import api_router
+from app.core.config import settings
+
+app = FastAPI(
+    title=settings.PROJECT_NAME,
+    openapi_url="/openapi.json",
+    docs_url="/docs",
+    redoc_url="/redoc",
+)
+
+# Set up CORS middleware
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=["*"],  # Allow all origins
+    allow_credentials=True,
+    allow_methods=["*"],  # Allow all methods
+    allow_headers=["*"],  # Allow all headers
+)
+
+# Include routers
+app.include_router(api_router)
+
+
+@app.get("/")
+async def root():
+    return {
+        "title": settings.PROJECT_NAME,
+        "docs": "/docs",
+        "health": "/health",
+    }
+
+
+@app.get("/health", status_code=200)
+async def health_check():
+    return {"status": "healthy"}
+
+
+if __name__ == "__main__":
+    uvicorn.run("main:app", host="0.0.0.0", port=8000, reload=True)

migrations/README

@@ -0,0 +1 @@
+Generic single-database configuration with an async dialect.

migrations/env.py

@@ -0,0 +1,85 @@
+import os
+import sys
+from logging.config import fileConfig
+
+from alembic import context
+from sqlalchemy import engine_from_config, pool
+
+# Add the parent directory to the path so we can import the app module
+sys.path.insert(0, os.path.dirname(os.path.dirname(__file__)))
+
+# import the models
+from app.db.base import Base  # noqa
+from app.models import Todo  # noqa
+
+# 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
+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/initial_migration.py

@@ -0,0 +1,37 @@
+"""initial migration
+
+Revision ID: 1a1f28d3e95a
+Revises:
+Create Date: 2023-09-01 00:00:00.000000
+
+"""
+import sqlalchemy as sa
+from alembic import op
+
+# revision identifiers, used by Alembic.
+revision = '1a1f28d3e95a'
+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(length=255), nullable=False),
+    sa.Column('description', sa.Text(), nullable=True),
+    sa.Column('completed', sa.Boolean(), nullable=True),
+    sa.Column('created_at', sa.DateTime(), nullable=True),
+    sa.Column('updated_at', sa.DateTime(), nullable=True),
+    sa.PrimaryKeyConstraint('id')
+    )
+    op.create_index(op.f('ix_todos_id'), 'todos', ['id'], unique=False)
+    # ### end Alembic commands ###
+
+
+def downgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.drop_index(op.f('ix_todos_id'), table_name='todos')
+    op.drop_table('todos')
+    # ### end Alembic commands ###

pyproject.toml

@@ -0,0 +1,24 @@
+[tool.ruff]
+target-version = "py38"
+line-length = 88
+
+[tool.ruff.lint]
+select = [
+    "E",  # pycodestyle errors
+    "W",  # pycodestyle warnings
+    "F",  # pyflakes
+    "I",  # isort
+    "B",  # flake8-bugbear
+    "C4", # flake8-comprehensions
+]
+ignore = [
+    "E203",  # whitespace before ':'
+    "E501",  # line too long (handled by black)
+    "B008",  # Do not perform function call in argument defaults (needed for FastAPI's Depends)
+]
+
+[tool.ruff.lint.isort]
+known-third-party = ["fastapi", "pydantic", "sqlalchemy"]
+
+[tool.ruff.lint.per-file-ignores]
+"__init__.py" = ["F401"] # unused imports

requirements.txt

@@ -0,0 +1,7 @@
+fastapi>=0.103.1
+uvicorn>=0.23.2
+sqlalchemy>=2.0.20
+alembic>=1.12.0
+pydantic>=2.3.0
+python-dotenv>=1.0.0
+ruff>=0.0.287