Implement Todo List API with FastAPI and SQLite

README.md

@@ -1,3 +1,161 @@
-# FastAPI Application
+# Todo List API
 
-This is a FastAPI application bootstrapped by BackendIM, the AI-powered backend generation platform.
+A simple Todo List API built with FastAPI and SQLite.
+
+## Features
+
+- Create, read, update, and delete todo items
+- Filter todo items by completion status
+- Pagination support
+- SQLite database with SQLAlchemy ORM
+- Database migrations with Alembic
+- Health check endpoint
+- OpenAPI documentation
+
+## Project Structure
+
+```
+todo-list-api/
+├── alembic.ini                # Alembic configuration
+├── app/                       # Main application package
+│   ├── api/                   # API endpoints
+│   │   └── routes/            # API route handlers
+│   │       ├── health.py      # Health check endpoint
+│   │       └── todo.py        # Todo endpoints
+│   ├── core/                  # Core application code
+│   │   └── config.py          # Application configuration
+│   ├── crud/                  # CRUD operations
+│   │   └── todo.py            # Todo CRUD operations
+│   ├── db/                    # Database related code
+│   │   └── session.py         # Database session setup
+│   ├── models/                # SQLAlchemy models
+│   │   └── todo.py            # Todo model
+│   └── schemas/               # Pydantic schemas
+│       └── todo.py            # Todo schemas
+├── main.py                    # Application entry point
+├── migrations/                # Alembic migrations
+│   ├── env.py                 # Alembic environment configuration
+│   ├── script.py.mako         # Migration script template
+│   └── versions/              # Migration script versions
+│       └── 001_create_todos_table.py  # Initial migration
+└── requirements.txt           # Python dependencies
+```
+
+## Requirements
+
+- Python 3.9+
+- FastAPI
+- SQLAlchemy
+- Pydantic
+- Alembic
+- Uvicorn
+
+## Installation
+
+1. Clone the repository:
+
+```bash
+git clone https://github.com/yourusername/todo-list-api.git
+cd todo-list-api
+```
+
+2. Install the required dependencies:
+
+```bash
+pip install -r requirements.txt
+```
+
+3. Run database migrations:
+
+```bash
+alembic upgrade head
+```
+
+## Running the Application
+
+Start the application with:
+
+```bash
+uvicorn main:app --reload
+```
+
+The API will be available at `http://localhost:8000`.
+
+## API Documentation
+
+After starting the application, you can access the interactive API documentation:
+
+- Swagger UI: `http://localhost:8000/docs`
+- ReDoc: `http://localhost:8000/redoc`
+
+## API Endpoints
+
+### Health Check
+
+- `GET /api/health`: Check if the API is healthy
+
+### Todo Operations
+
+- `GET /api/todos`: Get a list of todo items
+  - Query parameters:
+    - `skip`: Number of items to skip (pagination)
+    - `limit`: Maximum number of items to return (pagination)
+    - `completed`: Filter by completion status (optional)
+
+- `POST /api/todos`: Create a new todo item
+  - Request body: `TodoCreate` schema
+
+- `GET /api/todos/{todo_id}`: Get a specific todo item by ID
+
+- `PUT /api/todos/{todo_id}`: Update a specific todo item by ID
+  - Request body: `TodoUpdate` schema
+
+- `DELETE /api/todos/{todo_id}`: Delete a specific todo item by ID
+
+## Examples
+
+### Create a Todo
+
+```bash
+curl -X 'POST' \
+  'http://localhost:8000/api/todos' \
+  -H 'Content-Type: application/json' \
+  -d '{
+  "title": "Buy groceries",
+  "description": "Milk, eggs, bread",
+  "completed": false
+}'
+```
+
+### Get All Todos
+
+```bash
+curl -X 'GET' 'http://localhost:8000/api/todos'
+```
+
+### Get Completed Todos
+
+```bash
+curl -X 'GET' 'http://localhost:8000/api/todos?completed=true'
+```
+
+### Update a Todo
+
+```bash
+curl -X 'PUT' \
+  'http://localhost:8000/api/todos/1' \
+  -H 'Content-Type: application/json' \
+  -d '{
+  "completed": true
+}'
+```
+
+### Delete a Todo
+
+```bash
+curl -X 'DELETE' 'http://localhost:8000/api/todos/1'
+```
+
+## License
+
+MIT

alembic.ini

@@ -0,0 +1,102 @@
+# 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
+
+# sys.path path, will be prepended to sys.path if present.
+# defaults to the current working directory.
+prepend_sys_path = .
+
+# timezone to use when rendering the date within the migration file
+# as well as the filename.
+# If specified, requires the python-dateutil library that can be
+# installed by adding `alembic[tz]` to the pip requirements
+# 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.
+# The path separator used here should be the separator specified by "version_path_separator" below.
+# version_locations = %(here)s/bar:%(here)s/bat:migrations/versions
+
+# version path separator; As mentioned above, this is the character used to split
+# version_locations. The default within new alembic.ini files is "os", which uses os.pathsep.
+# If this key is omitted entirely, it falls back to the legacy behavior of splitting on spaces and/or commas.
+# Valid values for version_path_separator are:
+#
+# version_path_separator = :
+# version_path_separator = ;
+# version_path_separator = space
+version_path_separator = os  # Use os.pathsep. Default configuration used for new projects.
+
+# 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 REVISION_SCRIPT_FILENAME
+
+# 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/health.py

@@ -0,0 +1,9 @@
+from fastapi import APIRouter, status
+
+router = APIRouter(tags=["health"])
+
+
+@router.get("/health", status_code=status.HTTP_200_OK)
+async def health_check():
+    """Health check endpoint to verify the application is running."""
+    return {"status": "healthy"}

app/api/routes/todo.py

@@ -0,0 +1,88 @@
+from typing import Optional
+
+from fastapi import APIRouter, Depends, HTTPException, Query, status
+from sqlalchemy.orm import Session
+
+from app.crud import todo as todo_crud
+from app.db.session import get_db
+from app.schemas.todo import Todo, TodoCreate, TodoList, TodoUpdate
+
+router = APIRouter(tags=["todos"])
+
+
+@router.get("/todos", response_model=TodoList)
+async def get_todos(
+    skip: int = Query(0, ge=0, description="Number of items to skip"),
+    limit: int = Query(100, ge=1, le=100, description="Number of items to return"),
+    completed: Optional[bool] = Query(None, description="Filter by completion status"),
+    db: Session = Depends(get_db),
+):
+    """
+    Get a list of todo items with pagination and optional filtering by completion status.
+    """
+    todos = todo_crud.get_todos(db, skip=skip, limit=limit, completed=completed)
+    count = todo_crud.get_todos_count(db, completed=completed)
+    return {"items": todos, "count": count}
+
+
+@router.post("/todos", response_model=Todo, status_code=status.HTTP_201_CREATED)
+async def create_todo(
+    todo: TodoCreate,
+    db: Session = Depends(get_db),
+):
+    """
+    Create a new todo item.
+    """
+    return todo_crud.create_todo(db, todo)
+
+
+@router.get("/todos/{todo_id}", response_model=Todo)
+async def get_todo(
+    todo_id: int,
+    db: Session = Depends(get_db),
+):
+    """
+    Get a specific todo item by ID.
+    """
+    db_todo = todo_crud.get_todo(db, todo_id)
+    if db_todo is None:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail=f"Todo with ID {todo_id} not found",
+        )
+    return db_todo
+
+
+@router.put("/todos/{todo_id}", response_model=Todo)
+async def update_todo(
+    todo_id: int,
+    todo: TodoUpdate,
+    db: Session = Depends(get_db),
+):
+    """
+    Update a specific todo item by ID.
+    """
+    db_todo = todo_crud.update_todo(db, todo_id, todo)
+    if db_todo is None:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail=f"Todo with ID {todo_id} not found",
+        )
+    return db_todo
+
+
+@router.delete("/todos/{todo_id}", status_code=status.HTTP_204_NO_CONTENT, response_model=None)
+async def delete_todo(
+    todo_id: int,
+    db: Session = Depends(get_db),
+):
+    """
+    Delete a specific todo item by ID.
+    """
+    result = todo_crud.delete_todo(db, todo_id)
+    if result is None:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail=f"Todo with ID {todo_id} not found",
+        )
+    return None

app/core/config.py

@@ -0,0 +1,30 @@
+from pathlib import Path
+
+from pydantic_settings import BaseSettings
+
+
+class Settings(BaseSettings):
+    # Project settings
+    PROJECT_NAME: str = "Todo List API"
+    PROJECT_DESCRIPTION: str = "A simple Todo List API built with FastAPI and SQLite"
+    PROJECT_VERSION: str = "0.1.0"
+    
+    # API settings
+    API_PREFIX: str = "/api"
+    HOST: str = "0.0.0.0"
+    PORT: int = 8000
+    DEBUG: bool = True
+    
+    # CORS settings
+    CORS_ORIGINS: list[str] = ["*"]
+    
+    # Database settings
+    DB_DIR: Path = Path("/app") / "storage" / "db"
+    DATABASE_URL: str = f"sqlite:///{DB_DIR}/db.sqlite"
+    
+    class Config:
+        env_file = ".env"
+        case_sensitive = True
+
+
+settings = Settings()

app/crud/__init__.py

@@ -0,0 +1,17 @@
+from app.crud.todo import (
+    create_todo,
+    delete_todo,
+    get_todo,
+    get_todos,
+    get_todos_count,
+    update_todo,
+)
+
+__all__ = [
+    "create_todo",
+    "delete_todo",
+    "get_todo",
+    "get_todos",
+    "get_todos_count",
+    "update_todo",
+]

app/crud/todo.py

@@ -0,0 +1,72 @@
+from typing import Optional, Union
+
+from sqlalchemy import desc
+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 todo item by its ID."""
+    return db.query(Todo).filter(Todo.id == todo_id).first()
+
+
+def get_todos(
+    db: Session, 
+    skip: int = 0, 
+    limit: int = 100, 
+    completed: Optional[bool] = None
+) -> list[Todo]:
+    """Get a list of todo items, optionally filtered by completion status."""
+    query = db.query(Todo)
+    
+    if completed is not None:
+        query = query.filter(Todo.completed == completed)
+    
+    return query.order_by(desc(Todo.created_at)).offset(skip).limit(limit).all()
+
+
+def get_todos_count(db: Session, completed: Optional[bool] = None) -> int:
+    """Get the total count of todo items, optionally filtered by completion status."""
+    query = db.query(Todo)
+    
+    if completed is not None:
+        query = query.filter(Todo.completed == completed)
+    
+    return query.count()
+
+
+def create_todo(db: Session, todo: TodoCreate) -> Todo:
+    """Create a new todo item."""
+    db_todo = Todo(**todo.model_dump())
+    db.add(db_todo)
+    db.commit()
+    db.refresh(db_todo)
+    return db_todo
+
+
+def update_todo(db: Session, todo_id: int, todo: TodoUpdate) -> Optional[Todo]:
+    """Update an existing todo item."""
+    db_todo = get_todo(db, todo_id)
+    if db_todo is None:
+        return None
+    
+    update_data = todo.model_dump(exclude_unset=True)
+    for field, value in update_data.items():
+        setattr(db_todo, field, value)
+    
+    db.commit()
+    db.refresh(db_todo)
+    return db_todo
+
+
+def delete_todo(db: Session, todo_id: int) -> Union[bool, None]:
+    """Delete a todo item by its ID."""
+    db_todo = get_todo(db, todo_id)
+    if db_todo is None:
+        return None
+    
+    db.delete(db_todo)
+    db.commit()
+    return True

app/db/session.py

@@ -0,0 +1,30 @@
+from pathlib import Path
+
+from sqlalchemy import create_engine
+from sqlalchemy.ext.declarative import declarative_base
+from sqlalchemy.orm import sessionmaker
+
+from app.core.config import settings
+
+# Ensure directory exists
+Path(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()
+
+
+def get_db():
+    """Dependency for getting DB session."""
+    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 +1,17 @@
+from sqlalchemy import Boolean, Column, DateTime, Integer, String, Text
+from sqlalchemy.sql import func
+
+from app.db.session import Base
+
+
+class Todo(Base):
+    """SQLAlchemy Todo model."""
+    
+    __tablename__ = "todos"
+    
+    id = Column(Integer, primary_key=True, index=True)
+    title = Column(String(100), nullable=False)
+    description = Column(Text, nullable=True)
+    completed = Column(Boolean, default=False)
+    created_at = Column(DateTime(timezone=True), server_default=func.now())
+    updated_at = Column(DateTime(timezone=True), server_default=func.now(), onupdate=func.now())

app/schemas/__init__.py

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

app/schemas/todo.py

@@ -0,0 +1,50 @@
+from datetime import datetime
+from typing import Optional
+
+from pydantic import BaseModel, Field
+
+
+class TodoBase(BaseModel):
+    """Base Todo schema with common attributes."""
+    title: str = Field(..., min_length=1, max_length=100, description="Title of the todo item")
+    description: Optional[str] = Field(None, description="Detailed description of the todo item")
+    completed: bool = Field(False, description="Whether the todo item is completed")
+
+
+class TodoCreate(TodoBase):
+    """Schema for creating a new todo item."""
+    pass
+
+
+class TodoUpdate(BaseModel):
+    """Schema for updating an existing todo item."""
+    title: Optional[str] = Field(
+        None, 
+        min_length=1, 
+        max_length=100, 
+        description="Title of the todo item"
+    )
+    description: Optional[str] = Field(None, description="Detailed description of the todo item")
+    completed: Optional[bool] = Field(None, description="Whether the todo item is completed")
+
+
+class TodoInDB(TodoBase):
+    """Schema for a todo item as stored in the database."""
+    id: int
+    created_at: datetime
+    updated_at: datetime
+
+    class Config:
+        """Pydantic config."""
+        orm_mode = True
+
+
+class Todo(TodoInDB):
+    """Schema for a todo item returned by the API."""
+    pass
+
+
+class TodoList(BaseModel):
+    """Schema for a list of todo items."""
+    items: list[Todo]
+    count: int

main.py

@@ -0,0 +1,37 @@
+import uvicorn
+from fastapi import FastAPI
+from fastapi.middleware.cors import CORSMiddleware
+
+from app.api.routes.health import router as health_router
+from app.api.routes.todo import router as todo_router
+from app.core.config import settings
+
+app = FastAPI(
+    title=settings.PROJECT_NAME,
+    description=settings.PROJECT_DESCRIPTION,
+    version=settings.PROJECT_VERSION,
+    openapi_url=f"{settings.API_PREFIX}/openapi.json",
+    docs_url="/docs",
+    redoc_url="/redoc",
+)
+
+# Set CORS middleware
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=settings.CORS_ORIGINS,
+    allow_credentials=True,
+    allow_methods=["*"],
+    allow_headers=["*"],
+)
+
+# Include routers
+app.include_router(todo_router, prefix=settings.API_PREFIX)
+app.include_router(health_router, prefix=settings.API_PREFIX)
+
+if __name__ == "__main__":
+    uvicorn.run(
+        "main:app",
+        host=settings.HOST,
+        port=settings.PORT,
+        reload=settings.DEBUG,
+    )

migrations/env.py

@@ -0,0 +1,72 @@
+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 sys.path
+sys.path.insert(0, os.path.dirname(os.path.dirname(__file__)))
+
+# Import the SQLAlchemy models
+import app.models.todo  # noqa
+from app.db.session import Base
+
+# This is the Alembic Config object
+config = context.config
+
+# Interpret the config file for Python logging
+fileConfig(config.config_file_name)
+
+# Get SQLAlchemy metadata object
+target_metadata = Base.metadata
+
+
+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.
+    """
+    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,  # Enable batch mode 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 +1,26 @@
+"""${message}
+
+Revision ID: ${up_revision}
+Revises: ${down_revision | comma,n}
+Create Date: ${create_date}
+
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+${imports if imports else ""}
+
+# revision identifiers, used by Alembic.
+revision: str = ${repr(up_revision)}
+down_revision: Union[str, None] = ${repr(down_revision)}
+branch_labels: Union[str, Sequence[str], None] = ${repr(branch_labels)}
+depends_on: Union[str, Sequence[str], None] = ${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 +1,47 @@
+"""Create todos table
+
+Revision ID: 001
+Revises: 
+Create Date: 2023-05-21 12:00:00.000000
+
+"""
+from collections.abc import Sequence
+from typing import Union
+
+import sqlalchemy as sa
+from alembic import op
+
+# revision identifiers, used by Alembic.
+revision: str = '001'
+down_revision: Union[str, None] = None
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    op.create_table(
+        'todos',
+        sa.Column('id', sa.Integer(), nullable=False),
+        sa.Column('title', sa.String(length=100), nullable=False),
+        sa.Column('description', sa.Text(), nullable=True),
+        sa.Column('completed', sa.Boolean(), nullable=True, default=False),
+        sa.Column(
+            'created_at', 
+            sa.DateTime(timezone=True), 
+            server_default=sa.text('(CURRENT_TIMESTAMP)'), 
+            nullable=True
+        ),
+        sa.Column(
+            'updated_at', 
+            sa.DateTime(timezone=True), 
+            server_default=sa.text('(CURRENT_TIMESTAMP)'), 
+            nullable=True
+        ),
+        sa.PrimaryKeyConstraint('id')
+    )
+    op.create_index(op.f('ix_todos_id'), 'todos', ['id'], unique=False)
+
+
+def downgrade() -> None:
+    op.drop_index(op.f('ix_todos_id'), table_name='todos')
+    op.drop_table('todos')

pyproject.toml

@@ -0,0 +1,23 @@
+[tool.ruff]
+target-version = "py39"
+line-length = 100
+
+[tool.ruff.lint]
+select = [
+    "E",   # pycodestyle errors
+    "F",   # pyflakes
+    "I",   # isort
+    "C4",  # flake8-comprehensions
+    "B",   # flake8-bugbear
+    "UP",  # pyupgrade
+]
+ignore = [
+    "B008",  # do not perform function calls in argument defaults (FastAPI dependency injection)
+]
+
+[tool.ruff.lint.isort]
+known-third-party = ["fastapi", "pydantic", "sqlalchemy"]
+
+[tool.ruff.lint.flake8-quotes]
+docstring-quotes = "double"
+inline-quotes = "double"

requirements.txt

@@ -0,0 +1,7 @@
+fastapi>=0.95.0
+uvicorn>=0.21.1
+sqlalchemy>=2.0.0
+pydantic>=2.0.0
+alembic>=1.10.0
+python-dotenv>=1.0.0
+ruff>=0.0.262