app.py

from fastapi import FastAPI
from pydantic import BaseModel
from typing import Optional
from sqlalchemy import create_engine, Boolean, Column, Integer, String
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import scoped_session, sessionmaker

engine = create_engine('sqlite:///:memory:')
db_session = scoped_session(sessionmaker(autocommit=False, autoflush=False, bind=engine))
Base = declarative_base()
Base.query = db_session.query_property()

class Todo(Base):
    __tablename__ = 'todos'
    id = Column(Integer, primary_key=True)
    task = Column(String(50))
    done = Column(Boolean)

Base.metadata.create_all(bind=engine)

class TodoModel(BaseModel):
    id: Optional[int]
    task: str
    done: bool

app = FastAPI()

@app.get("/todos/")
async def read_todos():
    todos = Todo.query.all()
    return todos

@app.post("/todos/", response_model=TodoModel)
async def create_todo(todo: TodoModel):
    todo_obj = Todo(task=todo.task, done=todo.done)
    db_session.add(todo_obj)
    db_session.commit()
    return todo_obj

@app.put("/todos/{todo_id}", response_model=TodoModel)
async def update_todo(todo_id: int, todo: TodoModel):
    todo_obj = Todo.query.get(todo_id)
    if todo_obj is None:
        return {"error": "Todo not found"}
    todo_obj.task = todo.task
    todo_obj.done = todo.done
    db_session.commit()
    return todo_obj

@app.delete("/todos/{todo_id}")
async def delete_todo(todo_id: int):
    todo_obj = Todo.query.get(todo_id)
    if todo_obj is None:
        return {"error": "Todo not found"}
    db_session.delete(todo_obj)
    db_session.commit()
    return {"message": "Todo deleted"}