from sqlalchemy.ext.asyncio import AsyncSession
from sqlalchemy import select, update
from typing import Optional

from db.models import Product


class ProductRepository:
    async def get_product_by_id(
        self, session: AsyncSession, product_id: int
    ) -> Optional[Product]:
        stmt = select(Product).where(Product.id == product_id)
        return await session.scalar(stmt)

    async def get_product_by_category(
        self, session: AsyncSession, category_id: int, *, limit: int, offset: int
    ) -> list[Product]:
        stmt = (
            select(Product)
            .where(Product.category_id == category_id)
            .order_by(Product.id)
            .offset(offset)
            .limit(limit)
        )

        result = await session.scalars(stmt)

        return list(result)

    async def add_product_file_id(
        self, session: AsyncSession, product_id: int, *, file_id: str
    ) -> None:
        stmt = (
            update(Product.__table__)
            .where(Product.id == product_id)
            .where(Product.file_id is None)
            .values(file_id=file_id)
        )
        await session.execute(stmt)
        await session.commit()