# dao/student_dao.py
# 本文件封装对学生表的所有数据库操作（增、删、改、查）
from fastapi import HTTPException
from sqlalchemy.orm import Session
from model.student import Student
from scheme.students import StudentCreate, StudentUpdate


class StudentDAO:
    # 多条件查询学生列表（编号、姓名、班级等，条件可以叠加）
    @staticmethod
    def get_list(db: Session, sid=None, name=None, cid=None,
                 gender=None, education=None, page=1, size=10):
        query = db.query(Student).filter(Student.flag == 1)  # flag=1 才是有效数据
        # 传了哪个条件就追加哪个过滤条件
        if sid :
            query = query.filter(Student.sid == sid)
        if name:
            query = query.filter(Student.name.like(f"%{name}%"))  # 姓名模糊查询
        if cid :
            query = query.filter(Student.cid == cid)
        if gender:
            query=query.filter(Student.gender == gender)
        if education:
            query=query.filter(Student.education == education)
        total = query.count()                    # 先算总条数（分页要用）
        items = query.order_by(Student.sid).offset((page - 1) * size).limit(size).all()
        return total, items

    # 按学生id查单个学生
    @staticmethod
    def get_by_id(db: Session, sid: int):
        student = db.query(Student).filter(Student.sid == sid, Student.flag == 1).first()
        if not student:
            raise HTTPException(status_code=404, detail=f"学生 {sid} 不存在")
        return student

    # 新增学生
    @staticmethod
    def create(db: Session, data: StudentCreate):
        student = Student(**data.model_dump())
        student.flag = 1                  # 新数据默认是正常状态
        db.add(student)
        db.commit()
        db.refresh(student)               # 刷新后能拿到数据库生成的自增学号
        return student

    # 更新学生信息
    @staticmethod
    def update(db: Session, sid: int, data: StudentUpdate):
        update_data = data.model_dump(exclude_unset=True)
        db.query(Student) \
            .filter(Student.sid == sid) \
            .update(update_data)
        db.commit()
        return StudentDAO.get_by_id(db, sid)

    # 逻辑删除学生（flag 改为 0，不真删数据）
    @staticmethod
    def delete(db: Session, sid: int):
        student = StudentDAO.get_by_id(db, sid)
        student.flag = 0
        db.commit()
        db.refresh(student)
        return student