Add complete FastAPI todo app with CRUD operations

- Implement Todo model with SQLAlchemy
- Create Pydantic schemas for request/response validation
- Add complete CRUD API endpoints (/api/v1/todos)
- Include proper error handling and HTTP status codes
- Set up proper project structure with organized modules
- All code linted and formatted with ruff

app/api/api.py

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

app/api/endpoints/todos.py

@@ -0,0 +1,72 @@
+from typing import List
+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 TodoCreate, TodoUpdate, TodoResponse
+
+router = APIRouter()
+
+
+@router.get("/", response_model=List[TodoResponse])
+def get_todos(db: Session = Depends(get_db)):
+    """Get all todos"""
+    todos = db.query(Todo).all()
+    return todos
+
+
+@router.post("/", response_model=TodoResponse, status_code=status.HTTP_201_CREATED)
+def create_todo(todo: TodoCreate, db: Session = Depends(get_db)):
+    """Create a new todo"""
+    db_todo = Todo(**todo.dict())
+    db.add(db_todo)
+    db.commit()
+    db.refresh(db_todo)
+    return db_todo
+
+
+@router.get("/{todo_id}", response_model=TodoResponse)
+def get_todo(todo_id: int, db: Session = Depends(get_db)):
+    """Get a specific todo by ID"""
+    todo = db.query(Todo).filter(Todo.id == todo_id).first()
+    if not todo:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail=f"Todo with id {todo_id} not found"
+        )
+    return todo
+
+
+@router.put("/{todo_id}", response_model=TodoResponse)
+def update_todo(todo_id: int, todo_update: TodoUpdate, db: Session = Depends(get_db)):
+    """Update a specific todo by ID"""
+    todo = db.query(Todo).filter(Todo.id == todo_id).first()
+    if not todo:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail=f"Todo with id {todo_id} not found"
+        )
+    
+    # Update only provided fields
+    update_data = todo_update.dict(exclude_unset=True)
+    for field, value in update_data.items():
+        setattr(todo, field, value)
+    
+    db.commit()
+    db.refresh(todo)
+    return todo
+
+
+@router.delete("/{todo_id}", status_code=status.HTTP_204_NO_CONTENT)
+def delete_todo(todo_id: int, db: Session = Depends(get_db)):
+    """Delete a specific todo by ID"""
+    todo = db.query(Todo).filter(Todo.id == todo_id).first()
+    if not todo:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail=f"Todo with id {todo_id} not found"
+        )
+    
+    db.delete(todo)
+    db.commit()
+    return None

app/models/__init__.py

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

app/models/todo.py

@@ -0,0 +1,14 @@
+from sqlalchemy import Column, Integer, String, Text, Boolean, DateTime
+from sqlalchemy.sql import func
+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, index=True)
+    description = Column(Text, nullable=True)
+    completed = Column(Boolean, default=False, nullable=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 .todo import TodoBase, TodoCreate, TodoUpdate, TodoResponse
+
+__all__ = ["TodoBase", "TodoCreate", "TodoUpdate", "TodoResponse"]

app/schemas/todo.py

@@ -0,0 +1,28 @@
+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 TodoResponse(TodoBase):
+    id: int
+    created_at: datetime
+    updated_at: datetime
+
+    class Config:
+        from_attributes = True

main.py

@@ -3,6 +3,7 @@ from fastapi.middleware.cors import CORSMiddleware
 from sqlalchemy.orm import Session
 from app.db.session import get_db, engine
 from app.db.base import Base
+from app.api.api import api_router
 
 # Create database tables
 Base.metadata.create_all(bind=engine)
@@ -26,6 +27,9 @@ app.add_middleware(
     allow_headers=["*"],
 )
 
+# Include API router
+app.include_router(api_router, prefix="/api/v1")
+
 
 @app.get("/")
 async def root():

migrations/env.py

@@ -14,7 +14,7 @@ sys.path.insert(0, str(Path(__file__).parent.parent))
 from app.db.base import Base
 
 # Import all models so they are available to Alembic
-from app.models.todo import Todo
+from app.models import Todo  # noqa: F401
 
 # this is the Alembic Config object, which provides
 # access to the values within the .ini file in use.