# -*- coding: utf-8 -*-
"""题目-知识点映射（支持一题多知识点）"""
from datetime import datetime
from sqlalchemy import Column, Integer, DateTime, ForeignKey

from backend.database import Base


class QuestionKnowledgePoint(Base):
    __tablename__ = "question_knowledge_points"

    id = Column(Integer, primary_key=True, index=True)

    # 暂时关联到 questions 表，后续可扩展到更通用的题库表
    question_id = Column(Integer, ForeignKey("questions.id"), nullable=False, index=True)

    # 对应 schema.sql 中的 knowledge_points.id
    knowledge_point_id = Column(Integer, nullable=False, index=True)

    # 该知识点在本题中的权重（1=次要，2=一般，3=核心）
    weight = Column(Integer, default=1)

    created_at = Column(DateTime, default=datetime.utcnow)