from typing import List, Optional

from sqlalchemy.orm import Session

from app.models.item import Item
from app.schemas.item import ItemCreate, ItemUpdate


def get_item(db: Session, id: int) -> Optional[Item]:
    """
    Get an item by ID.
    """
    return db.query(Item).filter(Item.id == id).first()


def get_items(db: Session, skip: int = 0, limit: int = 100) -> List[Item]:
    """
    Get multiple items.
    """
    return db.query(Item).offset(skip).limit(limit).all()


def get_user_items(
    db: Session, owner_id: int, skip: int = 0, limit: int = 100
) -> List[Item]:
    """
    Get items for a specific user.
    """
    return (
        db.query(Item).filter(Item.owner_id == owner_id).offset(skip).limit(limit).all()
    )


def create_item(db: Session, obj_in: ItemCreate, owner_id: int) -> Item:
    """
    Create a new item.
    """
    db_obj = Item(
        title=obj_in.title,
        description=obj_in.description,
        owner_id=owner_id,
    )
    db.add(db_obj)
    db.commit()
    db.refresh(db_obj)
    return db_obj


def update_item(db: Session, db_obj: Item, obj_in: ItemUpdate) -> Item:
    """
    Update an item.
    """
    update_data = obj_in.dict(exclude_unset=True)

    for field, value in update_data.items():
        setattr(db_obj, field, value)

    db.add(db_obj)
    db.commit()
    db.refresh(db_obj)
    return db_obj


def delete_item(db: Session, id: int) -> None:
    """
    Delete an item.
    """
    item = db.query(Item).get(id)
    if item:
        db.delete(item)
        db.commit()