from sqlalchemy.orm import Session
from model.stu_model import Student
from sqlalchemy.exc import SQLAlchemyError
from schema.stu_schema import StudentCreateRequest,StudentUpdateRequest
def create_student(db: Session, student_create: StudentCreateRequest):

    try:
        db_student = Student(**student_create.model_dump())
        db.add(db_student)
        db.commit()
    except SQLAlchemyError:
        db.rollback()
        return None
    new_student = db.query(Student).filter(
        Student.stu_id == student_create.stu_id,
        Student.is_deleted == False).first()
    return new_student


def get_student_by_id(db: Session, stu_id: str):
    query = db.query(Student).filter(
        Student.stu_id == stu_id,
        Student.is_deleted == False)
    return query.first()


def get_student_list(db: Session, stu_id: str | None = None,
                     class_id: str = None, page: int = 1, page_size: int = 10, stu_name: str = None):
    page = max(1, page)
    page_size = max(1, min(100, page_size))
    query = db.query(Student).filter(Student.is_deleted == False)
    if stu_id:
        query = query.filter(Student.stu_id == stu_id)
    if stu_name:
        query = query.filter(Student.stu_name.like(f"%{stu_name}%"))
    if class_id:
        query = query.filter(Student.class_id == class_id)

    total = query.count()
    offset = (page - 1) * page_size
    db_student_list = query.offset(offset).limit(page_size).all()
    return total, db_student_list


def update_student(db: Session, stu_id: str, student_update: StudentUpdateRequest):
    try:
        db_student = get_student_by_id(db=db, stu_id=stu_id)
        if not db_student:
            return None
        update_data = student_update.model_dump(exclude_unset=True)
        for k, v in update_data.items():
            setattr(db_student, k, v)
        db.commit()
    except SQLAlchemyError:
        db.rollback()
        return None
    return db_student

def delete_student_logic(db: Session, stu_id: str):
    try:
        db_student = get_student_by_id(db, stu_id)
        if not db_student:
            return None
        db_student.is_deleted = True
        db.commit()
    except SQLAlchemyError:
        db.rollback()
        return None
    return db_student