from sqlalchemy.orm import Session

from model import Score, Student
from schema.score_schema import ScoreUpdate, ScoreCreate


#添加成绩
def create_score(
        db:Session,
        score_data:ScoreCreate,
):
    stu = db.query(Student).filter(Student.sid == score_data.student_id, Student.flag == 1).first()
    if stu is None:
        raise ValueError("该学生不存在")
    if score_data.exam_id not in (1, 2, 3):
        raise ValueError("考试次序不合法")
    if not isinstance(score_data.score, int) or not (0 <= score_data.score <= 100):
        raise ValueError("成绩不合法")
    exist = db.query(Score).filter(Score.student_id == score_data.student_id,Score.exam_id == score_data.exam_id,Score.flag == 1).first()
    if exist:
        return None
    new_score = Score(
        student_id=score_data.student_id,
        exam_id=score_data.exam_id,
        score=score_data.score,
        flag=1
    )
    #添加到数据库会话
    db.add(new_score)
    db.commit()
    #覆盖Python原始数据
    db.refresh(new_score)
    return new_score

#查询学生成绩
def search_score(
        db:Session,
        student_id:int,
        exam_id:int,
):
    stu = db.query(Student).filter(Student.sid == student_id, Student.flag == 1).first()
    if stu is None:
        raise ValueError("该学生不存在")
    if exam_id not in (1, 2, 3):
        raise ValueError("考试次序不合法")
    return db.query(Score).filter(
        Score.flag == 1,
        Score.student_id == student_id,
        Score.exam_id == exam_id
    ).all()

#修改成绩
def update_score(
        db:Session,
        student_id:int,
        exam_id:int,
        score_data:ScoreUpdate,
):
    stu = db.query(Student).filter(Student.sid == student_id, Student.flag == 1).first()
    if stu is None:
        raise ValueError("该学生不存在")
    if exam_id not in (1, 2, 3):
        raise ValueError("考试次序不合法")
    if not isinstance(score_data.score, int) or not (0 <= score_data.score <= 100):
        raise ValueError("成绩不合法")
    score = db.query(Score).filter(Score.student_id == student_id,Score.exam_id == exam_id,Score.flag == 1).first()
    if score is None:
        return None
    update_data = score_data.model_dump(exclude_unset=True)
    for k,v in update_data.items():
        setattr(score,k,v)
    db.commit()
    db.refresh(score)
    return score

#删除成绩
def delete_score(db:Session,student_id:int,exam_id:int):
    stu = db.query(Student).filter(Student.sid == student_id, Student.flag == 1).first()
    if stu is None:
        raise ValueError("该学生不存在")

    if exam_id not in (1, 2, 3):
        raise ValueError("考试次序不合法")

    score = db.query(Score).filter(
        Score.student_id == student_id,
        Score.flag == 1,
        Score.exam_id == exam_id
    ).first()
    if score is None:
        return None
    #逻辑删除，磁盘保留
    score.flag = 0
    db.commit()
    db.refresh(score)
    return score