from models.score import Score

def post_score_dao(data_dict, db):
    """新增成绩"""
    try:
        obj = Score(**data_dict)
        db.add(obj)
        db.commit()
    except Exception as e:
        print("新增成绩异常：", e)
        db.rollback()
        return False
    else:
        return True


def update_score_dao(score_id, db, updates):
    """修改成绩，query.update方式"""
    try:
        cnt = db.query(Score).filter(
            Score.id == score_id,
            Score.is_deleted == 0
        ).update(updates)
        if cnt == 0:
            db.rollback()
            return False
    except Exception as e:
        print("修改成绩异常：", e)
        db.rollback()
        return False
    else:
        db.commit()
        return True


def get_score_dao(score_id, student_id, exam_seq, page, page_size, db):
    """分页查询成绩，多条件过滤，只查未删除
    规则：
      - score_id == 0                → 查所有学生成绩（仅分页，不加 id 过滤）
      - 三个筛选条件全为空（None）   → 直接返回空，不查库
      - 其他情况                     → 按传入条件过滤
    """
    q = db.query(Score).filter(Score.is_deleted == 0)

    if score_id == 0:
        pass                                  # score_id=0 → 查全部（分页）
    elif score_id is None and not student_id and not exam_seq:
        return 0, []                          # 三个参数都没传 → 返回空
    else:
        if score_id:
            q = q.filter(Score.id == score_id)
        if student_id:
            q = q.filter(Score.student_id == student_id)
        if exam_seq:
            q = q.filter(Score.exam_seq == exam_seq)

    total = q.count()
    rows = q.offset((page - 1) * page_size).limit(page_size).all()

    res_list = [
        {
            "id": i.id,
            "student_id": i.student_id,
            "score": i.score,
            "exam_seq": i.exam_seq,
            "exam_date": i.exam_date,
            "remark": i.remark,
            "created_at": i.created_at,
            "updated_at": i.updated_at,
            "is_deleted": i.is_deleted
        }
        for i in rows
    ]
    return total, res_list






def delete_score_dao(score_id, db):
    try:
        cnt = db.query(Score).filter(
            Score.id == score_id,
            Score.is_deleted == 0
        ).update({"is_deleted": 1})     # ← 接住返回值
        if cnt == 0:                    # ← 关键：一行都没匹配到
            db.rollback()
            return False
    except Exception as err:
        print("删除成绩异常：", err)
        db.rollback()
        return False
    else:
        db.commit()
        return True


def exist_student_exam_dao(student_id, exam_seq, db):
    """校验：同一个学生+考试序次是否已经存在，用于联合唯一业务判断"""
    rec = db.query(Score).filter(
        Score.student_id == student_id,
        Score.exam_seq == exam_seq,
        Score.is_deleted == 0
    ).first()
    return rec is not None