from typing import Optional, List
from sqlalchemy.orm import Session
from ..models.knowledge_point_model import KnowledgePointModel
from .base_store import BaseStore


class KnowledgePointStore(BaseStore[KnowledgePointModel]):
    """
    知识点存储类，继承自BaseStore
    提供知识点相关的特定操作
    """

    def __init__(self, db: Session):
        super().__init__(db, KnowledgePointModel)

    def get_by_subject(self, subject: str) -> List[KnowledgePointModel]:
        """根据学科获取知识点列表"""
        return self.db.query(
            self.model).filter(self.model.subject == subject).all()

    def get_by_level(self, level: int) -> List[KnowledgePointModel]:
        """根据难度等级获取知识点列表"""
        return self.db.query(
            self.model).filter(self.model.level == level).all()

    def get_root_knowledge_points(self) -> List[KnowledgePointModel]:
        """获取所有根知识点"""
        return self.db.query(
            self.model).filter(self.model.parent_id == None).all()

    def get_child_knowledge_points(
            self, parent_id: int) -> List[KnowledgePointModel]:
        """根据父知识点ID获取子知识点列表"""
        return self.db.query(
            self.model).filter(self.model.parent_id == parent_id).all()

    def get_knowledge_point_tree(self) -> List[KnowledgePointModel]:
        """获取完整的知识点树结构"""
        # 先获取所有知识点
        all_points = self.db.query(self.model).all()
        # 构建树结构
        point_dict = {point.id: point for point in all_points}
        for point in all_points:
            if point.parent_id:
                parent = point_dict.get(point.parent_id)
                if parent:
                    if not hasattr(parent, 'children'):
                        parent.children = []
                    parent.children.append(point)
        # 返回根节点
        return [point for point in all_points if not point.parent_id]