# dao/students_dao.py
# 本文件封装对 model 表的所有数据库操作（增、删、改、查）


from sqlalchemy.orm import Session
from fastapi import HTTPException
from model.c_lass import Classinfo
from model.advisors import Advisor
from model.students import Student
from scheme.students import StudentCreate, StudentUpdate
from typing import Optional, List


class StudentDAO:

    @staticmethod
    def inspect_class_id_unq(db: Session, class_id: int):
        """校验班级是否存在：去 c_lass 表查"""
        return db.query(Classinfo).filter(Classinfo.class_id == class_id).first()

    @staticmethod
    def inspect_advisor_id_unq(db: Session, advisor_id: int):
        """校验顾问是否存在：去 advisors 表查"""
        return db.query(Advisor).filter(Advisor.advisor_id == advisor_id).first()

    @staticmethod
    def create_student(db: Session, obj_in: StudentCreate):
        """新增学生，检查学号唯一性"""
        exist = db.query(Student).filter(Student.stu_id == obj_in.stu_id).first()
        # 只按 stu_id 判断，且包含逻辑删除的记录
        if exist:
            if exist.is_deleted == 1:
                raise HTTPException(status_code=400, detail="该学号已被占用（处于逻辑删除状态），请先恢复")
            raise HTTPException(status_code=400, detail="该学生已存在")
        db_obj = Student(**obj_in.model_dump())
        try:
            db.add(db_obj)
            db.commit()
            db.refresh(db_obj)
        except Exception:
            db.rollback()
            raise
        return db_obj

    @staticmethod
    def get_students_all(db: Session, skip: int = 0, limit: int = 100):
        """分页查询全部学生"""
        return db.query(Student).filter(Student.is_deleted == 0).offset(skip).limit(limit).all()

    @staticmethod
    def get_student_by_id(db: Session, stu_id: int):
        """根据学生编号单条查询"""
        return db.query(Student).filter(Student.is_deleted == 0,
               Student.stu_id == stu_id).first()

    @staticmethod
    def query_multi_condition(
            db: Session,
            stu_id: Optional[int] = None,
            stu_name: Optional[str] = None,
            class_id: Optional[int] = None,
            skip: int = 0,
            limit: int = 100
    ) :
        q = db.query(Student).filter(Student.is_deleted == 0)
        """多条件选择性查询"""
        # 只有参数不为None的时候，才加上查询条件
        if stu_id is not None:
            q = q.filter(Student.stu_id == stu_id)
        if stu_name is not None:
            q = q.filter(Student.stu_name.like(f"%{stu_name}%"))
        if class_id is not None:
            q = q.filter(Student.class_id == class_id)

        q = q.offset(skip).limit(limit)
        return q.all()

    @staticmethod
    def update_student(db: Session,stu_id:int, obj: StudentUpdate):
        db_obj = db.query(Student).filter(Student.stu_id == stu_id,
            Student.is_deleted == 0).first()
        if not db_obj:
            raise HTTPException(status_code=404, detail="学生数据不存在或已删除")

        update_data = obj.model_dump(exclude_unset=True)
        for field, value in update_data.items():
            setattr(db_obj, field, value)
        try:
            db.commit()
            db.refresh(db_obj)
        except Exception:
            db.rollback()
            raise
        return db_obj

    @staticmethod
    def delete_student(db: Session, stu_id: int):
        db_obj = db.query(Student).filter(Student.stu_id == stu_id,
                Student.is_deleted == 0).first()
        if not db_obj:
            raise HTTPException(status_code=404, detail="学生数据不存在或已删除")

        db_obj.is_deleted = 1
        try:
            db.commit()
            db.refresh(db_obj)
        except Exception:
            db.rollback()
            raise
        return True  # 返回布尔值，而不是 dict