from sqlalchemy import select, delete
from sqlalchemy.exc import SQLAlchemyError
from sqlalchemy.ext.asyncio import AsyncSession
from sqlalchemy.orm import joinedload

from models.library import Mistake, Subject
from schemas.mistake import MistakeResponse, MistakeRequest
from service import subject_service


async def list_mistakes(subject: str, db: AsyncSession) -> list[MistakeResponse]:
    subject_id = await subject_service.get_subject_by_name(db, subject)
    stmt = (
        select(Mistake)
        .options(joinedload(Mistake.subject))
        .where(Mistake.subject_id == subject_id)
        .order_by(Mistake.id.desc())
    )

    mistakes = (await db.execute(stmt)).scalars().unique().all()

    return [
        MistakeResponse(
            id=mistake.id,
            type=mistake.type,
            question=mistake.question,
            options=mistake.options,
            answer=mistake.answer,
        )
        for mistake in mistakes
    ]


async def add_mistakes(db: AsyncSession, subject: str, data: list[MistakeRequest]):
    subject_id = await subject_service.get_subject_by_name(db, subject)

    subject = (
        await db.execute(
            select(Subject).where(Subject.id == subject_id)
        )
    ).scalar_one_or_none()

    if not subject:
        raise ValueError("Subject not found")

    mistakes = [
        Mistake(
            subject_id=subject_id,
            type=item.type,
            question=item.question,
            options=item.options,
            answer=item.answer,
        )
        for item in data
    ]

    try:
        db.add_all(mistakes)
        await db.flush()
        await db.commit()
        return True
    except SQLAlchemyError:
        await db.rollback()
        raise


async def remove_mistake(db: AsyncSession, mistake_id: int) -> bool:
    await db.execute(delete(Mistake).where(Mistake.id == mistake_id))
    await db.commit()

    return True