from fastapi.encoders import jsonable_encoder
from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession


class CRUDBase:

    def __init__(self, model):
        self.model = model

    async def get(
            self,
            obj_id: int,
            session: AsyncSession
    ):
        db_obj = await session.execute(
            select(self.model).where(
                self.model.db == obj_id
            )
        )
        return db_obj.scalars().first()

    async def get_multi(self, session: AsyncSession):
        db_objs = await session.execute(select(self.model))
        return db_objs.scalars().all()

    async def create(self,
                     obj_in,
                     session: AsyncSession):
        obj_in_data = obj_in
        db_obj = self.model(**obj_in_data)
        session.add(db_obj)
        await session.commit()
        await session.refresh(db_obj)
        return db_obj


    async def update(
            self,
            db_obj,
            obj_in,
            session: AsyncSession
    ):
        obj_data = jsonable_encoder(db_obj)
        update_data = obj_in.dict(exclude_unsets=True)
        for field in obj_data:
            if field in update_data:
                setattr(db_obj, field, update_data[field])
        session.add(db_obj)
        await session.commit()
        await session.refresh(db_obj)
        return db_obj