# backend/app/services/category_service.py
from sqlalchemy.orm import Session
from fastapi import HTTPException, status
from ..models import Category, Spider

class CategoryService:
    @staticmethod
    def get_category_by_id(db: Session, category_id: int) -> Category:
        category = db.query(Category).filter(Category.id == category_id).first()
        if not category:
            raise HTTPException(
                status_code=status.HTTP_404_NOT_FOUND,
                detail="分类不存在"
            )
        return category
    
    @staticmethod
    def check_category_name_exists(db: Session, name: str, exclude_id: int = None) -> bool:
        query = db.query(Category).filter(Category.name == name)
        if exclude_id:
            query = query.filter(Category.id != exclude_id)
        return query.first() is not None
    
    @staticmethod
    def get_spider_count(db: Session, category_id: int) -> int:
        return db.query(Spider).filter(Spider.category_id == category_id).count()