from typing import Optional

from sqlalchemy import select, Sequence
from sqlalchemy.ext.asyncio import AsyncSession

from app.domain.models import Contest


class ContestsRepository:
    def __init__(self, db: AsyncSession):
        self.db = db

    async def get_all(self) -> Sequence[Contest]:
        stmt = select(Contest)
        result = await self.db.execute(stmt)
        return result.scalars().all()

    async def get_by_id(self, contest_id: int) -> Optional[Contest]:
        stmt = select(Contest).filter_by(id=contest_id)
        result = await self.db.execute(stmt)
        return result.scalars().first()

    async def create(self, contest: Contest) -> Contest:
        self.db.add(contest)
        await self.db.commit()
        await self.db.refresh(contest)
        return contest

    async def update(self, contest: Contest) -> Contest:
        await self.db.merge(contest)
        await self.db.commit()
        return contest

    async def delete(self, contest: Contest) -> Contest:
        await self.db.delete(contest)
        await self.db.commit()
        return contest