# backend/modules/todo/service.py
from sqlalchemy.orm import Session
from . import models, schemas
from modules.auth.models import User # Assuming User model is in auth.models
from fastapi import HTTPException, status

def create_todo(db: Session, todo: schemas.TodoCreate, user: User):
    db_todo = models.Todo(**todo.dict(), owner_id=user.id)
    db.add(db_todo)
    db.commit()
    db.refresh(db_todo)
    return db_todo

def get_todos(db: Session, user: User, skip: int = 0, limit: int = 100):
    return db.query(models.Todo).filter(models.Todo.owner_id == user.id).offset(skip).limit(limit).all()

def get_todo(db: Session, todo_id: int, user: User):
    db_todo = db.query(models.Todo).filter(models.Todo.id == todo_id, models.Todo.owner_id == user.id).first()
    if db_todo is None:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Todo not found")
    return db_todo

def update_todo(db: Session, todo_id: int, todo_update: schemas.TodoUpdate, user: User):
    db_todo = get_todo(db=db, todo_id=todo_id, user=user) # Reuse get_todo to check ownership and existence
    update_data = todo_update.dict(exclude_unset=True)
    for key, value in update_data.items():
        setattr(db_todo, key, value)
    db.commit()
    db.refresh(db_todo)
    return db_todo

def delete_todo(db: Session, todo_id: int, user: User):
    db_todo = get_todo(db=db, todo_id=todo_id, user=user) # Reuse get_todo to check ownership and existence
    db.delete(db_todo)
    db.commit()
    return db_todo