# dao/scores_dao.py
# 成绩表的数据访问层（录入、修改、删除、查询 + 60分红线预警）
from typing import List, Optional, Tuple

from sqlalchemy.orm import Session

from model.scores import Score
from model.students import Student
from scheme.scores import ScoreAdd


class ScoreDAO:
    WARNING_LINE = 60  # 成绩红线

    @staticmethod
    def get_one(db: Session, stu_id: int, exam_id: int, include_deleted: bool = False) -> Optional[Score]:
        """获取指定学生某次考核的成绩（复合主键查询）"""
        query = db.query(Score).filter(Score.stu_id == stu_id, Score.exam_id == exam_id)
        if not include_deleted:
            query = query.filter(Score.is_deleted == 0)
        return query.first()

    @staticmethod
    def add_score(db: Session, score_data: ScoreAdd) -> Score:
        """录入成绩（调用方需先校验学生存在与复合主键冲突）"""
        db_score = Score(**score_data.model_dump(), is_deleted=0)
        db.add(db_score)
        db.commit()
        db.refresh(db_score)
        return db_score

    @staticmethod
    def update_score(db: Session, stu_id: int, exam_id: int, new_score: float) -> Optional[Score]:
        """修改指定学生的某次成绩"""
        db_score = ScoreDAO.get_one(db, stu_id, exam_id)
        if db_score is None:
            return None
        db_score.score = new_score
        db_score.is_deleted = 0  # 若曾被软删除，修改视为恢复
        db.commit()
        db.refresh(db_score)
        return db_score

    @staticmethod
    def delete_score(db: Session, stu_id: int, exam_id: int) -> bool:
        """
        逻辑删除指定学生的某次成绩
        :return: True 成功 / False 不存在或已删除
        """
        db_score = ScoreDAO.get_one(db, stu_id, exam_id)
        if db_score is None:
            return False
        db_score.is_deleted = 1
        db.commit()
        return True

    @staticmethod
    def get_by_student(db: Session, stu_id: int) -> List[Score]:
        """获取学生的全部成绩（按考核序次排序）"""
        return (
            db.query(Score)
            .filter(Score.stu_id == stu_id, Score.is_deleted == 0)
            .order_by(Score.exam_id)
            .all()
        )

    @staticmethod
    def get_by_exam(db: Session, exam_id: int, skip: int = 0, limit: int = 100) -> Tuple[int, List[Score]]:
        """按考核序次查询成绩列表（分页）"""
        query = db.query(Score).filter(Score.exam_id == exam_id, Score.is_deleted == 0)
        total = query.count()
        items = query.order_by(Score.stu_id).offset(skip).limit(limit).all()
        return total, items

    @staticmethod
    def attach_student_name(db: Session, score: Score) -> None:
        """把学生姓名附加到 Score 对象上（供响应模型冗余展示）"""
        student = db.query(Student).filter(Student.stu_id == score.stu_id).first()
        score.stu_name = student.stu_name if student else None

    @staticmethod
    def build_score_item(score: Score, stu_name: Optional[str] = None) -> dict:
        """组装成绩响应字典：附带红线预警标记"""
        return {
            "stu_id": score.stu_id,
            "exam_id": score.exam_id,
            "score": score.score,
            "stu_name": stu_name,
            "is_warning": score.score is not None and score.score < ScoreDAO.WARNING_LINE,
        }