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

from app.models.source_case import CaseBase, CaseExamItem


class CaseRepository:
    """病例只读仓储：读取已发布病例、模式扩展数据和固定检查项目。"""

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

    def get_active_case(self, case_id: int) -> CaseBase | None:
        """病例读取：读取病例主表及训练所需的扩展表、评分规则和检查项目。"""
        stmt = (
            select(CaseBase)
            .options(
                selectinload(CaseBase.traditional_case),
                selectinload(CaseBase.teaching_case),
                selectinload(CaseBase.scoring_rules),
                selectinload(CaseBase.exam_items),
            )
            .where(CaseBase.id == case_id, CaseBase.status == 1, CaseBase.publish_status == 1)
        )
        return self.db.scalar(stmt)

    def get_exam_items(self, case_id: int) -> list[CaseExamItem]:
        """检查项目：读取当前病例下全部可申请检查检验项目。"""
        stmt = select(CaseExamItem).where(CaseExamItem.case_id == case_id).order_by(CaseExamItem.display_order)
        return list(self.db.scalars(stmt).all())

    def get_exam_item(self, case_id: int, item_code: str) -> CaseExamItem | None:
        """检查结果：按病例和项目编码读取数据库中的固定结果。"""
        stmt = select(CaseExamItem).where(CaseExamItem.case_id == case_id, CaseExamItem.item_code == item_code)
        return self.db.scalar(stmt)