from sqlalchemy.future import select
from sqlalchemy.ext.asyncio import AsyncSession
from . import models

async def get_or_create_user(db: AsyncSession, telegram_id: str):
    result = await db.execute(select(models.User).where(models.User.telegram_id == telegram_id))
    user = result.scalar_one_or_none()
    if not user:
        user = models.User(telegram_id=telegram_id)
        db.add(user)
        await db.commit()
        await db.refresh(user)
    return user

async def add_message(db: AsyncSession, user, role, content):
    msg = models.Message(user_id=user.id, role=role, content=content)
    db.add(msg)
    await db.commit()
    await db.refresh(msg)
    return msg

async def get_conversation(db: AsyncSession, user, limit=10):
    result = await db.execute(
        select(models.Message)
        .where(models.Message.user_id == user.id)
        .order_by(models.Message.timestamp.desc())
        .limit(limit)
    )
    return list(reversed(result.scalars().all()))