1/dao/wl_class_dao.py

from sqlalchemy.orm import Session
from model.wl_class_model import Class_
from model.wl_student_model import Student
from fastapi import HTTPException

from model.wl_teacher_model import Teacher


# 1. 新增班级
def create_class(db: Session, class_data: dict):
    new_class = Class_(**class_data)
    db.add(new_class)
    db.commit()
    db.refresh(new_class)
    return new_class


# 2. 查询班级列表（你的亮点：查出了班主任和授课老师）
def get_classes(db: Session, skip: int = 0, limit: int = 100):
    # 先查出所有没被删除的班级
    class_list = db.query(Class_).filter(Class_.is_deleted == 0).offset(skip).limit(limit).all()
    #下面的部分等导入老师模块后解除注释
    # # 循环每个班级，去老师表里找对应的老师
    for c in class_list:
        # 找班主任（role是"班主任"的第一个老师）
        head_teacher = db.query(Teacher).filter(
            Teacher.class_id == c.class_id,
            Teacher.role == "班主任",
            Teacher.is_deleted == 0
        ).first()

        # 找授课老师（可能有多个，用逗号拼起来）
        course_teachers = db.query(Teacher).filter(
            Teacher.class_id == c.class_id,
            Teacher.role == "任课",
            Teacher.is_deleted == 0
        ).all()

        # 把查到的名字塞给班级对象，方便传给前端
        c.head_teacher_name = head_teacher.t_name if head_teacher else "暂无"
        # 下面这两行是初学者常用的拼接字符串写法（代码改了，这里的注释没动）
        if course_teachers:
            names = [t.t_name for t in course_teachers]
            c.course_teacher_names = "，".join(names)
        else:
            c.course_teacher_names = "暂无"

    return class_list


# 3. 根据ID查班级
def get_class_by_id(db: Session, class_id: int):
    return db.query(Class_).filter(Class_.class_id == class_id, Class_.is_deleted == 0).first()


# 4. 修改班级信息
def update_class(db: Session, class_id: int, class_data: dict):
    db_class = get_class_by_id(db, class_id)
    if not db_class:
        return None

    # 前端传了什么，就改什么（防止把没传的字段改成空值）
    for key, value in class_data.items():
        setattr(db_class, key, value)

    db.commit()
    db.refresh(db_class)
    return db_class


# 5. 逻辑删除班级（你的亮点：安全检查）
def delete_class(db: Session, class_id: int):
    db_class = get_class_by_id(db, class_id)
    if not db_class:
        return {"code": 404, "msg": "班级不存在"}

    # 检查1：班里还有学生吗？（只要有1个，就不给删）
    student = db.query(Student).filter(
        Student.class_id == class_id,
        Student.is_deleted == 0
    ).first()
    if student:
        raise HTTPException(status_code=400, detail="该班级还有学生，不能删除！")
    #解除注释后做了改动
    # 检查2：班里还有老师吗？
    teacher = db.query(Teacher).filter(
        Teacher.class_id == class_id,
        Teacher.is_deleted == 0
    ).first()
    if teacher:
        raise HTTPException(status_code=400, detail="该班级还有老师，不能删除！")

    # 检查通过，开始逻辑删除（贴个已删除标签）
    db_class.is_deleted = 1
    db.commit()
    return {"code": 200, "msg": "班级删除成功"}