from pymysql import IntegrityError
from models.class_model import Class,Teacher
from sqlalchemy.orm import Session
def add_class_dao(c,db):
    try:
        head_teacher = db.query(Teacher).filter(Teacher.id == c['ht_id']).first()
        if head_teacher is None:
           return False, '指定的班主任不存在'
        class_teacher = db.query(Teacher).filter(Teacher.id == c['t_id']).first()
        if class_teacher is None:
           return False, '指定的授课老师不存在'
        if db.query(Class).filter(
                Class.class_id == c['class_id'],#如果请求体传进来的classid在表里找的到
                Class.is_deleted==0 #且没有处于软删除状态
        ).first():
            return False, '班级编号已存在'
        new_class = Class(**c)
        db.add(new_class)
        db.commit()
        return True,new_class
    except Exception as e:
        db.rollback()
        print('创建失败：',repr(e))
        return False,str(e)
def update_class_dao(id,update_data,db):
    try:
        rows = db.query(Class).filter(Class.id == id).update(update_data)
    except Exception as e:
        db.rollback()
        print('更新失败：', repr(e))
        return False, str(e)
    else:
        db.commit()
        return rows
'''
def get_class_dao(id,db,page,page_size):
        q = db.query(Class)
        if id:
            q = q.filter(Class.id == id,Class.is_deleted==0)
        rows = q.offset((page-1)*page_size ).limit(page_size).all()
        if rows:
            return[{'class_id':i.id,'class_no':i.class_no,'class_name':i.class_name,'ht_id':i.ht_id,'t_id':i.t_id,'start_time':i.start_time}for i in rows]
'''
def get_class_list_dao(db: Session, page: int, page_size: int, **filters):
    #软删除过滤
    q = db.query(Class).filter(Class.is_deleted == 0)

    # 精确匹配字段
    if filters.get("class_no"):
        q = q.filter(Class.class_id == filters["class_id"])
    if filters.get("ht_id") is not None:
        q = q.filter(Class.ht_id == filters["ht_id"])
    if filters.get("t_id") is not None:
        q = q.filter(Class.t_id == filters["t_id"])

    # 模糊匹配字段（例如班级名称）
    if filters.get("class_name"):
        q = q.filter(Class.class_name.like(f"%{filters['class_name']}%"))

    # 获取满足条件的总记录数（分页必备）
    total = q.count()

    # 分页查询
    rows = q.offset((page - 1) * page_size).limit(page_size).all()

    items = [ #如果匹配不到，则会返回空列表
        {
            'id': i.id,
            'class_id': i.class_id,
            'class_name': i.class_name,
            'ht_id': i.ht_id,
            't_id': i.t_id,
            'start_time': i.start_time
        }
        for i in rows
    ]
    return total, items
def get_class_by_id_dao(id: int, db: Session):
    i = db.query(Class).filter(Class.id == id, Class.is_deleted == 0).first()
    if not i:
        return None
    return {
        'id': i.id,
        'class_id': i.class_id,
        'class_name': i.class_name,
        'ht_id': i.ht_id,
        't_id': i.t_id,
        'start_time': i.start_time
    }
def delete_class_dao(id,db): #软删除
    try:
        rows = (db.query(Class)
                .filter(Class.id == id,Class.is_deleted==0)#只匹配还没处于软删除状态的行
                .update({Class.is_deleted:1},synchronize_session=False))#软删除就是把这个字段改成True
    except Exception as e:
        db.rollback()
        print('删除失败：', repr(e))
        return False, str(e)
    else:
        db.commit()
        return rows
def hard_delete_class_dao(id,db): #物理删除
    try:
        rows = (db.query(Class).filter(Class.id == id).delete(synchronize_session=False))
        db.commit()
        return rows
    except IntegrityError:
        db.rollback()
        return False, '该班级被其他数据引用，无法彻底删除'
    except Exception as e:
        db.rollback()
        print('物理删除失败', repr(e))
        return False, str(e)
def class_no_exist(class_id,db):
    return (db.query(Class)
            .filter(Class.class_id == class_id,Class.is_deleted==0)
            .first() is not None
            )