from typing import Optional

from sqlalchemy.orm import Session, joinedload

from app.crud.base import CRUDBase
from app.models.cart import Cart, CartItem
from app.schemas.cart import CartCreate, CartItemCreate, CartItemUpdate


class CRUDCart(CRUDBase[Cart, CartCreate, CartCreate]):
    def get_by_user_id(self, db: Session, *, user_id: int) -> Optional[Cart]:
        return db.query(Cart).filter(Cart.user_id == user_id).first()

    def get_or_create_cart(self, db: Session, *, user_id: int) -> Cart:
        cart = self.get_by_user_id(db, user_id=user_id)
        if not cart:
            cart = self.create(db, obj_in=CartCreate(user_id=user_id))
        return cart

    def get_cart_with_items(self, db: Session, *, user_id: int) -> Optional[Cart]:
        return (
            db.query(Cart)
            .filter(Cart.user_id == user_id)
            .options(joinedload(Cart.items).joinedload(CartItem.product))
            .first()
        )


class CRUDCartItem(CRUDBase[CartItem, CartItemCreate, CartItemUpdate]):
    def create_or_update_cart_item(
        self, db: Session, *, cart_id: int, product_id: int, quantity: int
    ) -> CartItem:
        cart_item = (
            db.query(CartItem)
            .filter(CartItem.cart_id == cart_id, CartItem.product_id == product_id)
            .first()
        )

        if cart_item:
            cart_item.quantity = quantity
            db.add(cart_item)
            db.commit()
            db.refresh(cart_item)
            return cart_item
        else:
            return self.create(
                db,
                obj_in=CartItemCreate(cart_id=cart_id, product_id=product_id, quantity=quantity)
            )

    def remove_cart_item(
        self, db: Session, *, cart_id: int, product_id: int
    ) -> None:
        db.query(CartItem).filter(
            CartItem.cart_id == cart_id, CartItem.product_id == product_id
        ).delete()
        db.commit()

    def clear_cart(self, db: Session, *, cart_id: int) -> None:
        db.query(CartItem).filter(CartItem.cart_id == cart_id).delete()
        db.commit()


cart = CRUDCart(Cart)
cart_item = CRUDCartItem(CartItem)