from typing import Optional

from sqlalchemy import select

from .base import BaseRepository
from ..models import UsageMetric


class UsageMetricRepository(BaseRepository[UsageMetric]):
    model = UsageMetric

    async def get_or_create(self, key: str) -> UsageMetric:
        result = await self.session.execute(select(UsageMetric).where(UsageMetric.key == key))
        instance = result.scalars().first()
        if instance is None:
            instance = UsageMetric(key=key, value=0)
            self.session.add(instance)
            await self.session.flush()
        return instance