# dao/score_dao.py
# 本文件封装对学生成绩表的所有数据库操作（增、删、改、查）
from fastapi import HTTPException
from sqlalchemy import and_
from sqlalchemy.orm import Session

from model.student_score import Score
from scheme.scores import ScoreCreate, ScoreUpdate


class ScoreDAO:

    # 根据学生id、考试次数查询有效成绩（flag=1）
    @staticmethod
    def get_by_id(db: Session, sid: int, exam_num: int):
        score = db.query(Score).filter(and_(Score.sid == sid, Score.exam_num == exam_num, Score.flag == 1)
        ).first()
        if score:
            return score
        raise HTTPException(status_code=404, detail="学生分数不存在")

    # 查询某个学生的所有考试成绩
    @staticmethod
    def get_by_student(db: Session, sid: int):
        return (db.query(Score)
                .filter(Score.sid == sid, Score.flag == 1).order_by(Score.exam_num).all())

    # 录入成绩
    @staticmethod
    def create(db: Session, data: ScoreCreate):
        # 同一个学生同一次考试只能有一条有效成绩
        exist = db.query(Score).filter(and_(Score.sid == data.sid, Score.exam_num == data.exam_num, Score.flag == 1)).first()
        if exist:
            raise HTTPException(status_code=400,
                                detail=f"学生 {data.sid} 第 {data.exam_num} 次成绩已存在，请使用修改接口")
        score = Score(sid=data.sid, exam_num=data.exam_num, score=data.score, flag=1)
        db.add(score)
        db.commit()
        db.refresh(score)
        return score

    # 根据学生id和考试次数更新成绩
    @staticmethod
    def update(db: Session, sid: int, exam_num: int, score_data: ScoreUpdate):
        update_data = score_data.model_dump()
        db.query(Score) \
            .filter(Score.sid == sid) \
            .update(update_data)
        db.commit()          # 提交事务
        return ScoreDAO.get_by_id(db, sid, exam_num)

    # 根据学生id和考试次数逻辑删除（flag 改为 0）
    @staticmethod
    def delete(db: Session, sid: int, exam_num: int):
        db_score = ScoreDAO.get_by_id(db, sid, exam_num)
        db_score.flag = 0     # 标记为已删除
        db.commit()
        db.refresh(db_score)
        return db_score