Create simple todo app API with FastAPI and SQLite

README.md

@@ -1,3 +1,77 @@
-# FastAPI Application
+# Todo App API
 
-This is a FastAPI application bootstrapped by BackendIM, the AI-powered backend generation platform.
+A simple todo application API built with FastAPI and SQLite.
+
+## Features
+
+- Create, read, update, and delete todo items
+- Health check endpoint
+- SQLite database with Alembic migrations
+- Pydantic data validation
+- Interactive API documentation
+
+## Project Structure
+
+```
+todoapp/
+├── app/
+│   ├── api/
+│   │   ├── endpoints/
+│   │   │   ├── health.py
+│   │   │   └── todos.py
+│   │   └── api.py
+│   ├── core/
+│   │   └── config.py
+│   ├── crud/
+│   │   └── todo.py
+│   ├── db/
+│   │   ├── deps.py
+│   │   └── session.py
+│   ├── models/
+│   │   └── todo.py
+│   └── schemas/
+│       └── todo.py
+├── migrations/
+│   ├── versions/
+│   │   └── a3bfb446d052_create_todos_table.py
+│   ├── env.py
+│   └── script.py.mako
+├── alembic.ini
+├── main.py
+└── requirements.txt
+```
+
+## Setup
+
+1. Clone the repository
+
+2. Install dependencies:
+```bash
+pip install -r requirements.txt
+```
+
+3. Run the application:
+```bash
+uvicorn main:app --reload
+```
+
+## 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
+
+### Todos
+
+- `GET /api/v1/todos/`: Get all todos
+- `POST /api/v1/todos/`: Create a new todo
+- `GET /api/v1/todos/{id}`: Get a specific todo
+- `PUT /api/v1/todos/{id}`: Update a todo
+- `DELETE /api/v1/todos/{id}`: Delete a todo
+
+### Health
+
+- `GET /api/v1/health/`: Check API health status

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/api.py

@@ -0,0 +1,7 @@
+from fastapi import APIRouter
+
+from app.api.endpoints import health, todos
+
+api_router = APIRouter()
+api_router.include_router(todos.router, prefix="/todos", tags=["todos"])
+api_router.include_router(health.router, prefix="/health", tags=["health"])

app/api/endpoints/health.py

@@ -0,0 +1,25 @@
+from fastapi import APIRouter, Depends
+from sqlalchemy import text
+from sqlalchemy.orm import Session
+
+from app.db.deps import get_db
+
+router = APIRouter()
+
+
+@router.get("/")
+def health_check(db: Session = Depends(get_db)):
+    """
+    Health check endpoint.
+    """
+    # Check database connection
+    try:
+        db.execute(text("SELECT 1"))
+        db_status = "ok"
+    except Exception as e:
+        db_status = f"error: {e!s}"
+
+    return {
+        "status": "ok",
+        "database": db_status,
+    }

app/api/endpoints/todos.py

@@ -0,0 +1,93 @@
+from typing import Any, List
+
+from fastapi import APIRouter, Depends, HTTPException, status
+from sqlalchemy.orm import Session
+
+from app import crud
+from app.db.deps import get_db
+from app.schemas.todo import Todo, TodoCreate, TodoUpdate
+
+router = APIRouter()
+
+
+@router.get("/", response_model=List[Todo])
+def read_todos(
+    db: Session = Depends(get_db),
+    skip: int = 0,
+    limit: int = 100,
+) -> Any:
+    """
+    Retrieve todos.
+    """
+    todos = crud.get_todos(db, skip=skip, limit=limit)
+    return todos
+
+
+@router.post("/", response_model=Todo, status_code=status.HTTP_201_CREATED)
+def create_todo(
+    *,
+    db: Session = Depends(get_db),
+    todo_in: TodoCreate,
+) -> Any:
+    """
+    Create new todo.
+    """
+    todo = crud.create_todo(db=db, todo_in=todo_in)
+    return todo
+
+
+@router.get("/{id}", response_model=Todo)
+def read_todo(
+    *,
+    db: Session = Depends(get_db),
+    id: int,
+) -> Any:
+    """
+    Get todo by ID.
+    """
+    todo = crud.get_todo(db=db, todo_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=Todo)
+def update_todo(
+    *,
+    db: Session = Depends(get_db),
+    id: int,
+    todo_in: TodoUpdate,
+) -> Any:
+    """
+    Update a todo.
+    """
+    todo = crud.get_todo(db=db, todo_id=id)
+    if not todo:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="Todo not found",
+        )
+    todo = crud.update_todo(db=db, todo_id=id, todo_in=todo_in)
+    return todo
+
+
+@router.delete("/{id}", response_model=Todo)
+def delete_todo(
+    *,
+    db: Session = Depends(get_db),
+    id: int,
+) -> Any:
+    """
+    Delete a todo.
+    """
+    todo = crud.get_todo(db=db, todo_id=id)
+    if not todo:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="Todo not found",
+        )
+    todo = crud.delete_todo(db=db, todo_id=id)
+    return todo

app/core/config.py

@@ -0,0 +1,27 @@
+from typing import List, Union
+
+from pydantic import AnyHttpUrl, validator
+from pydantic_settings import BaseSettings
+
+
+class Settings(BaseSettings):
+    API_V1_STR: str = "/api/v1"
+    PROJECT_NAME: str = "Todo App"
+    
+    # CORS Configuration
+    BACKEND_CORS_ORIGINS: List[Union[str, AnyHttpUrl]] = []
+
+    @validator("BACKEND_CORS_ORIGINS", pre=True)
+    def assemble_cors_origins(cls, v: Union[str, List[str]]) -> Union[List[str], 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)
+    
+    class Config:
+        case_sensitive = True
+        env_file = ".env"
+
+
+settings = Settings()

app/crud/__init__.py

@@ -0,0 +1,4 @@
+from app.crud.todo import create_todo, delete_todo, get_todo, get_todos, update_todo
+
+# For easy access to all crud operations
+__all__ = ["create_todo", "delete_todo", "get_todo", "get_todos", "update_todo"]

app/crud/todo.py

@@ -0,0 +1,56 @@
+from typing import Any, Dict, List, Optional, Union
+
+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]:
+    return db.query(Todo).filter(Todo.id == todo_id).first()
+
+
+def get_todos(db: Session, skip: int = 0, limit: int = 100) -> List[Todo]:
+    return db.query(Todo).offset(skip).limit(limit).all()
+
+
+def create_todo(db: Session, todo_in: TodoCreate) -> Todo:
+    db_todo = Todo(
+        title=todo_in.title,
+        description=todo_in.description,
+        completed=todo_in.completed
+    )
+    db.add(db_todo)
+    db.commit()
+    db.refresh(db_todo)
+    return db_todo
+
+
+def update_todo(
+    db: Session, todo_id: int, todo_in: Union[TodoUpdate, Dict[str, Any]]
+) -> Optional[Todo]:
+    db_todo = get_todo(db, todo_id)
+    if not db_todo:
+        return None
+    
+    todo_data = (
+        todo_in if isinstance(todo_in, dict) else todo_in.dict(exclude_unset=True)
+    )
+    
+    for key, value in todo_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) -> Optional[Todo]:
+    db_todo = get_todo(db, todo_id)
+    if not db_todo:
+        return None
+    
+    db.delete(db_todo)
+    db.commit()
+    return db_todo

app/db/deps.py

@@ -0,0 +1,16 @@
+from typing import Generator
+
+from sqlalchemy.orm import Session
+
+from app.db.session import SessionLocal
+
+
+def get_db() -> Generator[Session, None, None]:
+    """
+    Dependency for getting a database session.
+    """
+    db = SessionLocal()
+    try:
+        yield db
+    finally:
+        db.close()

app/db/session.py

@@ -0,0 +1,18 @@
+from pathlib import Path
+
+from sqlalchemy import create_engine
+from sqlalchemy.ext.declarative import declarative_base
+from sqlalchemy.orm import sessionmaker
+
+DB_DIR = Path("/app") / "storage" / "db"
+DB_DIR.mkdir(parents=True, exist_ok=True)
+
+SQLALCHEMY_DATABASE_URL = f"sqlite:///{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/models/__init__.py

@@ -0,0 +1,4 @@
+from app.models.todo import Todo
+
+# For easy access to all models
+__all__ = ["Todo"]

app/models/todo.py

@@ -0,0 +1,15 @@
+from sqlalchemy import Boolean, Column, DateTime, Integer, String
+from sqlalchemy.sql import func
+
+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, server_default=func.now())
+    updated_at = Column(DateTime, server_default=func.now(), onupdate=func.now())

app/schemas/__init__.py

@@ -0,0 +1,4 @@
+from app.schemas.todo import Todo, TodoBase, TodoCreate, TodoUpdate
+
+# For easy access to all schemas
+__all__ = ["Todo", "TodoBase", "TodoCreate", "TodoUpdate"]

app/schemas/todo.py

@@ -0,0 +1,33 @@
+from datetime import datetime
+from typing import Optional
+
+from pydantic import BaseModel
+
+
+class TodoBase(BaseModel):
+    title: str
+    description: Optional[str] = None
+    completed: bool = False
+
+
+class TodoCreate(TodoBase):
+    pass
+
+
+class TodoUpdate(BaseModel):
+    title: Optional[str] = None
+    description: Optional[str] = None
+    completed: Optional[bool] = None
+
+
+class TodoInDBBase(TodoBase):
+    id: int
+    created_at: datetime
+    updated_at: datetime
+
+    class Config:
+        from_attributes = True
+
+
+class Todo(TodoInDBBase):
+    pass

main.py

@@ -0,0 +1,32 @@
+
+from fastapi import FastAPI
+from fastapi.middleware.cors import CORSMiddleware
+
+from app.api.api import api_router
+from app.core.config import settings
+
+app = FastAPI(
+    title=settings.PROJECT_NAME,
+    description="A simple TODO API application",
+    version="0.1.0",
+    openapi_url=f"{settings.API_V1_STR}/openapi.json",
+    docs_url="/docs",
+    redoc_url="/redoc",
+)
+
+# 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)
+
+if __name__ == "__main__":
+    import uvicorn
+    
+    uvicorn.run("main:app", host="0.0.0.0", port=8000, reload=True)

migrations/README

@@ -0,0 +1,3 @@
+Generic single-database configuration with Alembic.
+
+This directory contains the Alembic migration scripts for the Todo App.

migrations/env.py

@@ -0,0 +1,78 @@
+from logging.config import fileConfig
+
+from alembic import context
+from sqlalchemy import engine_from_config, pool
+
+from app.db.session 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.
+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/a3bfb446d052_create_todos_table.py

@@ -0,0 +1,49 @@
+"""Create todos table
+
+Revision ID: a3bfb446d052
+Revises: 
+Create Date: 2023-07-01 12:00:00.000000
+
+"""
+import sqlalchemy as sa
+from alembic import op
+
+# revision identifiers, used by Alembic.
+revision = 'a3bfb446d052'
+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(), 
+            server_default=sa.text('(CURRENT_TIMESTAMP)'), 
+            nullable=False
+        ),
+        sa.Column(
+            'updated_at', 
+            sa.DateTime(), 
+            server_default=sa.text('(CURRENT_TIMESTAMP)'), 
+            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,<0.101.0
+uvicorn>=0.22.0,<0.23.0
+sqlalchemy>=2.0.0,<3.0.0
+alembic>=1.11.0,<1.12.0
+pydantic>=2.0.0,<3.0.0
+python-dotenv>=1.0.0,<2.0.0
+ruff>=0.0.287

ruff.toml

@@ -0,0 +1,60 @@
+# Exclude a variety of commonly ignored directories.
+exclude = [
+    ".bzr",
+    ".direnv",
+    ".eggs",
+    ".git",
+    ".git-rewrite",
+    ".hg",
+    ".mypy_cache",
+    ".nox",
+    ".pants.d",
+    ".pytype",
+    ".ruff_cache",
+    ".svn",
+    ".tox",
+    ".venv",
+    "__pypackages__",
+    "_build",
+    "buck-out",
+    "build",
+    "dist",
+    "node_modules",
+    "venv",
+]
+
+# Same as Black.
+line-length = 88
+
+# Assume Python 3.8
+target-version = "py38"
+
+[lint]
+# Allow unused variables when underscore-prefixed.
+dummy-variable-rgx = "^(_+|(_+[a-zA-Z0-9_]*[a-zA-Z0-9]+?))$"
+
+# Allow autofix for all enabled rules (when `--fix`) is provided.
+fixable = ["ALL"]
+unfixable = []
+
+# Select all rules by default (E, F, B, I, ARG, C4, ASYNC, EXE, ISC, LOG, RUF, SLF)
+select = ["E", "F", "B", "I", "C", "N", "RUF"]
+ignore = [
+    # Ignore B008 (function call in argument defaults) because this is a standard pattern in FastAPI
+    "B008",
+    # Ignore N805 (first argument of a method should be named 'self') for pydantic validators
+    "N805",
+]
+
+[format]
+# Like Black, use double quotes for strings.
+quote-style = "double"
+
+# Like Black, indent with spaces, rather than tabs.
+indent-style = "space"
+
+# Like Black, respect magic trailing commas.
+skip-magic-trailing-comma = false
+
+# Like Black, automatically detect the appropriate line ending.
+line-ending = "auto"