from sqlalchemy import select
from sqlalchemy.orm import Session, selectinload

from app.models.source_case import CaseBase


class TeachingRepository:
    """教学互动仓储：读取 case_base + teaching_case 以及评分相关扩展数据。"""

    def __init__(self, db: Session) -> None:
        self.db = db

    def get_active_teaching_case(self, case_id: int) -> CaseBase | None:
        """教学病例读取：校验病例已发布、已启用且存在 teaching_case 扩展。"""
        stmt = (
            select(CaseBase)
            .options(
                selectinload(CaseBase.teaching_case),
                selectinload(CaseBase.traditional_case),
                selectinload(CaseBase.scoring_rules),
            )
            .where(CaseBase.id == case_id, CaseBase.status == 1, CaseBase.publish_status == 1)
        )
        case = self.db.scalar(stmt)
        return case if case and case.teaching_case else None