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

from app.models.user import User


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

    async def get_by_id(self, user_id: int) -> Optional[User]:
        result = await self.db.execute(select(User).where(User.id == user_id))
        return result.scalar_one_or_none()

    async def get_by_username(self, username: str) -> Optional[User]:
        result = await self.db.execute(select(User).where(User.username == username))
        return result.scalar_one_or_none()

    async def get_all(self) -> List[User]:
        result = await self.db.execute(select(User))
        return list(result.scalars().all())

    async def create(self, data: dict) -> User:
        user = User(**data)
        self.db.add(user)
        await self.db.flush()
        return user

    async def update(self, user_id: int, data: dict) -> Optional[User]:
        user = await self.get_by_id(user_id)
        if not user:
            return None
        for key, value in data.items():
            setattr(user, key, value)
        await self.db.flush()
        return user

    async def delete(self, user_id: int) -> bool:
        user = await self.get_by_id(user_id)
        if not user:
            return False
        await self.db.delete(user)
        return True