from sqlalchemy.orm import Session
from models.employment import Employment
from schemas.employment import EmploymentCreate, EmploymentUpdate, EmploymentResponse


def create_employment(db, obj_in):
    # obj_in是Pydantic对象(EmploymentCreate)
    """新增就业信息：一个学生只能存在一条就业记录"""
    try:
        db_obj = Employment(**obj_in.model_dump())
        db.add(db_obj)
        db.commit()
        db.refresh(db_obj)

        resp = EmploymentResponse(id=db_obj.id
                                  ,student_id=db_obj.student_id
                                  ,employment_status=db_obj.employment_status
                                  ,employment_open_date=db_obj.employment_open_date
                                  ,offer_date=db_obj.offer_date
                                  ,company_name=db_obj.company_name
                                  ,salary=db_obj.salary
                                  ,remark=db_obj.remark
                                  ,created_at=db_obj.created_at
                                  ,updated_at=db_obj.updated_at)
        return resp.model_dump()

    except Exception:
        db.rollback()
        return None


def get_employment_by_id(db, eid):
    """根据主键id查询就业详情，过滤逻辑删除"""
    try:
        db_obj = db.query(Employment).filter(Employment.id == eid
                                             ,Employment.is_deleted == 0).first()
        if not db_obj:
            return None

        resp = EmploymentResponse(id=db_obj.id
                                  ,student_id=db_obj.student_id
                                  ,employment_status=db_obj.employment_status
                                  ,employment_open_date=db_obj.employment_open_date
                                  ,offer_date=db_obj.offer_date
                                  ,company_name=db_obj.company_name
                                  ,salary=db_obj.salary
                                  ,remark=db_obj.remark
                                  ,created_at=db_obj.created_at
                                  ,updated_at=db_obj.updated_at)
        return resp.model_dump()
    except Exception:
        return None


def get_employment_by_student_id(db, student_id):
    """根据学生id查询就业信息，过滤逻辑删除"""
    try:
        db_obj = db.query(Employment).filter(Employment.student_id == student_id
                                             ,Employment.is_deleted == 0).first()
        if not db_obj:
            return None

        resp = EmploymentResponse(id=db_obj.id
                                  ,student_id=db_obj.student_id
                                  ,employment_status=db_obj.employment_status
                                  ,employment_open_date=db_obj.employment_open_date
                                  ,offer_date=db_obj.offer_date
                                  ,company_name=db_obj.company_name
                                  ,salary=db_obj.salary
                                  ,remark=db_obj.remark
                                  ,created_at=db_obj.created_at
                                  ,updated_at=db_obj.updated_at)
        return resp.model_dump()
    except Exception:
        return None


def get_employment_list(db, company_name=None, salary_min=None, salary_max=None, skip=0, limit=20):
    """就业列表查询；支持公司名模糊、薪资范围筛选；只查询is_deleted=0"""
    try:
        query = db.query(Employment).filter(Employment.is_deleted == 0)
        if company_name:
            query = query.filter(Employment.company_name.like(f"%{company_name}%"))
        if salary_min is not None:
            query = query.filter(Employment.salary >= salary_min)
        if salary_max is not None:
            query = query.filter(Employment.salary <= salary_max)

        total = query.count()
        records = query.offset(skip).limit(limit).all()

        dict_list = []
        for item in records:
            resp = EmploymentResponse(id=item.id
                                      ,student_id=item.student_id
                                      ,employment_status=item.employment_status
                                      ,employment_open_date=item.employment_open_date
                                      ,offer_date=item.offer_date
                                      ,company_name=item.company_name
                                      ,salary=item.salary
                                      ,remark=item.remark
                                      ,created_at=item.created_at
                                      ,updated_at=item.updated_at)
            dict_list.append(resp.model_dump())

        return dict_list, total
    except Exception:
        return [], 0


def update_employment(db, eid, obj_in):
    """修改就业信息，只更新传入的字段"""
    try:
        db_obj_raw = db.query(Employment).filter(Employment.id == eid
                                                 ,Employment.is_deleted == 0).first()
        if db_obj_raw is None:
            return None

        update_dict = obj_in.model_dump(exclude_unset=True)
        db.query(Employment).filter(Employment.id == eid
                                    ,Employment.is_deleted == 0).update(update_dict)

        db.commit()
        db.refresh(db_obj_raw)

        resp = EmploymentResponse(id=db_obj_raw.id
                                  ,student_id=db_obj_raw.student_id
                                  ,employment_status=db_obj_raw.employment_status
                                  ,employment_open_date=db_obj_raw.employment_open_date
                                  ,offer_date=db_obj_raw.offer_date
                                  ,company_name=db_obj_raw.company_name
                                  ,salary=db_obj_raw.salary
                                  ,remark=db_obj_raw.remark
                                  ,created_at=db_obj_raw.created_at
                                  ,updated_at=db_obj_raw.updated_at)
        return resp.model_dump()

    except Exception:
        db.rollback()
        return None


def delete_employment_logic(db, eid):
    """逻辑删除，只修改is_deleted=1，不做物理删除"""
    try:
        db_obj_raw = db.query(Employment).filter(Employment.id == eid
                                                 ,Employment.is_deleted == 0).first()
        if db_obj_raw is None:
            return False
        db_obj_raw.is_deleted = 1
        db.commit()
        return True
    except Exception:
        db.rollback()
        return False