LWX/ai_teaching_system/backend/services/question_parser.py

# -*- coding: utf-8 -*-
"""问题解析与意图识别：将口语化问题转为结构化查询与类型标签

基于 jieba 分词 + 初中化学领域词库 + 规则进行轻量级解析，
为后续知识图谱检索与大模型提示词提供结构化信息。
"""
from enum import Enum
from typing import Any, Dict, List

try:
    import jieba
except ImportError:  # 运行环境若未安装 jieba，则退化为纯规则模式
    jieba = None  # type: ignore


class QuestionType(str, Enum):
    """问题类型枚举：概念理解、实验操作、习题求解等"""

    CONCEPT = "concept"
    EXPERIMENT = "experiment"
    EXERCISE = "exercise"
    EQUATION = "equation"  # 方程式书写/配平/离子方程式
    ION_COEXIST = "ion_coexist"  # 离子共存/能否大量共存
    OTHER = "other"


# 初中化学核心主题词与其关联的知识图谱扩展检索词
_TOPIC_KG_EXPANSIONS: Dict[str, List[str]] = {
    # 复分解反应条件示例：扩展到沉淀/气体/水、离子共存规则、溶解性表等
    "复分解反应": [
        "复分解反应",
        "复分解反应条件",
        "生成沉淀",
        "生成气体",
        "生成水",
        "离子共存规则",
        "酸碱盐溶解性表",
        "离子反应",
    ],
    "离子反应": [
        "离子反应",
        "生成沉淀",
        "生成气体",
        "生成水",
        "离子共存规则",
        "酸碱盐溶解性表",
    ],
    "氧化还原反应": [
        "氧化还原反应",
        "化合价变化",
        "得电子",
        "失电子",
        "氧化剂",
        "还原剂",
    ],
    "中和反应": [
        "中和反应",
        "酸碱反应",
        "放热",
        "盐和水",
        "酸碱指示剂",
        "滴定",
    ],
    "酸碱指示剂": [
        "酸碱指示剂",
        "酚酞",
        "石蕊",
        "甲基橙",
        "指示剂变色范围",
    ],
    "物质的量": [
        "物质的量",
        "摩尔",
        "摩尔质量",
        "阿伏伽德罗常数",
        "气体摩尔体积",
    ],
    "溶液": [
        "溶液",
        "溶质",
        "溶剂",
        "质量分数",
        "溶解度",
        "饱和溶液",
    ],
    # 氧气及其制取与性质
    "氧气": [
        "氧气",
        "实验室制氧气",
        "高锰酸钾制氧气",
        "制取氧气的化学方程式",
        "氧气的物理性质",
        "氧气的化学性质",
        "氧气的制备和性质实验",
        "燃烧与灭火",
    ],
    # 二氧化碳及相关实验
    "二氧化碳": [
        "二氧化碳",
        "实验室制二氧化碳",
        "二氧化碳的物理性质",
        "二氧化碳的化学性质",
        "二氧化碳的制备和性质实验",
        "澄清石灰水",
    ],
    # 氧化还原的易错点补充：学生常说“氧化还原”而不是完整说“氧化还原反应”
    "氧化还原": [
        "氧化还原反应",
        "氧化还原",
        "化合价变化",
        "氧化剂",
        "还原剂",
    ],
    # 中和相关的常见混淆点
    "中和": [
        "中和反应",
        "酸碱中和",
        "酸碱指示剂",
        "盐和水",
    ],
    # 金属活动性顺序与置换反应
    "金属活动性顺序": [
        "金属活动性顺序",
        "置换反应",
        "金属与酸反应",
        "金属与盐溶液反应",
    ],
    # 气体制备与收集方法
    "气体制备与收集": [
        "实验室制氧气",
        "实验室制二氧化碳",
        "排水集气法",
        "向上排空气法",
        "向下排空气法",
        "气体的干燥",
    ],
    # 酸碱盐整体主题
    "酸碱盐": [
        "酸",
        "碱",
        "盐",
        "酸碱中和",
        "酸碱指示剂",
        "中和反应",
    ],
}


# 初中化学专业词汇词库（仅做识别，不直接决定题型）
_DOMAIN_TERMS: Dict[str, str] = {
    # 物质构成
    "原子": "structure",
    "分子": "structure",
    "离子": "structure",
    "元素": "structure",
    "原子核": "structure",
    "核外电子": "structure",
    "氧气": "substance",
    "空气": "substance",
    # 氧化还原
    "氧化还原反应": "redox",
    "氧化剂": "redox",
    "还原剂": "redox",
    "化合价": "redox",
    "得电子": "redox",
    "失电子": "redox",
    "氧化还原": "redox",
    "氧化反应": "redox",
    "还原反应": "redox",
    # 电解质、电离
    "电解质": "electrolyte",
    "弱电解质": "electrolyte",
    "强电解质": "electrolyte",
    "电离": "electrolyte",
    "离子反应": "electrolyte",
    # 溶液
    "溶液": "solution",
    "溶质": "solution",
    "溶剂": "solution",
    "溶解度": "solution",
    "饱和溶液": "solution",
    "不饱和溶液": "solution",
    "质量分数": "solution",
    # 酸碱盐与指示剂
    "酸": "acid_base",
    "碱": "acid_base",
    "盐": "acid_base",
    "中和反应": "acid_base",
    "酸碱指示剂": "acid_base",
    "酚酞": "acid_base",
    "石蕊": "acid_base",
    "甲基橙": "acid_base",
    "中和": "acid_base",
    "酸碱中和": "acid_base",
    "酸性": "acid_base",
    "碱性": "acid_base",
    "pH": "acid_base",
    # 物质的量与计算
    "物质的量": "calc",
    "摩尔": "calc",
    "摩尔质量": "calc",
    "阿伏伽德罗常数": "calc",
    "气体摩尔体积": "calc",
    "溶液配制": "calc",
    # 常见实验与装置
    "高锰酸钾": "experiment",
    "高锰酸钾制氧气": "experiment",
    "实验室制氧气": "experiment",
    "实验室制二氧化碳": "experiment",
    "检验氧气": "experiment",
    "检验二氧化碳": "experiment",
    "酒精灯": "experiment",
    "量筒": "experiment",
    "滴定管": "experiment",
    "排水集气法": "experiment",
    "向上排空气法": "experiment",
    "向下排空气法": "experiment",
    "集气瓶": "experiment",
    "试管": "experiment",
    "烧杯": "experiment",
    "锥形瓶": "experiment",
    "坩埚": "experiment",
    "蒸发皿": "experiment",
    "漏斗": "experiment",
    "滤纸": "experiment",
    "玻璃棒": "experiment",
    "集气": "experiment",
    "过滤": "experiment",
    "蒸发": "experiment",
    "蒸馏": "experiment",
    # 反应类型与典型情景
    "化合反应": "reaction_type",
    "分解反应": "reaction_type",
    "置换反应": "reaction_type",
    "复分解反应": "reaction_type",
    "燃烧": "reaction_type",
    # 常见物质与实验现象
    "二氧化碳": "substance",
    "氢气": "substance",
    "氮气": "substance",
    "水": "substance",
    "石灰水": "substance",
    "澄清石灰水": "substance",
    # 典型初中化学实验情景
    "镁条燃烧": "experiment",
    "镁条在空气中燃烧": "experiment",
    "铁丝在氧气中燃烧": "experiment",
    "铁钉生锈": "experiment",
    "水的电解": "experiment",
    "锌和盐酸反应": "experiment",
    "锌粒与盐酸反应": "experiment",
}


_EXPERIMENT_KEYWORDS = [
    "实验",
    "装置",
    "步骤",
    "操作",
    "需要注意",
    "注意事项",
    "现象",
    "为什么要",
    "为啥要",
    "为啥要塞",
    "怎么做",
    "如何操作",
    "收集气体",
    "收集方式",
    "排水集气法",
    "向上排空气法",
    "向下排空气法",
    "装配",
    "组装",
    "点燃",
    "熄灭",
    "实验室制氧气",
    "实验室制二氧化碳",
    "检验氧气",
    "检验二氧化碳",
]

_EXERCISE_KEYWORDS = [
    "求",
    "计算",
    "质量",
    "体积",
    "浓度",
    "配制",
    "生成多少",
    "生成的气体",
    "生成的沉淀",
    "x 的值",
    "已知",
]

_CONCEPT_KEYWORDS = [
    "是什么",
    "定义",
    "本质",
    "特征",
    "条件",
    "意义",
    "原因",
    "道理",
]


def _guess_question_type(q: str) -> QuestionType:
    """根据关键词粗略区分问题类型"""
    # 先识别方程式/离子共存类型（你选择先只打标签，求解交给大模型）
    if "化学方程式" in q or "离子方程式" in q or "配平" in q:
        return QuestionType.EQUATION
    if "能否大量共存" in q or "能否共存" in q or "是否能共存" in q:
        return QuestionType.ION_COEXIST

    for kw in _EXPERIMENT_KEYWORDS:
        if kw in q:
            return QuestionType.EXPERIMENT
    for kw in _EXERCISE_KEYWORDS:
        if kw in q:
            return QuestionType.EXERCISE
    for kw in _CONCEPT_KEYWORDS:
        if kw in q:
            return QuestionType.CONCEPT
    # 若包含“为什么/为啥”等多为概念或原理说明
    if "为什么" in q or "为啥" in q:
        return QuestionType.CONCEPT
    return QuestionType.OTHER


def _extract_topic_keywords(q: str) -> List[str]:
    """基于规则提取与初中化学相关的核心主题/关键词

    这里采用简单的子串匹配与规则扩展，后续可以接入分词与专业词库替换。
    """
    keywords: List[str] = []

    # 1) 使用 jieba 分词（若可用）从分词结果中匹配专业词汇
    if jieba is not None:
        for w in jieba.lcut(q):
            if w in _DOMAIN_TERMS and w not in keywords:
                keywords.append(w)

    # 2) 针对复分解反应等重点考点做显式主题识别（子串匹配兜底）
    if "复分解反应" in q and "复分解反应" not in keywords:
        keywords.append("复分解反应")
    if "离子反应" in q and "离子反应" not in keywords:
        keywords.append("离子反应")
    if "高锰酸钾" in q and "高锰酸钾" not in keywords:
        keywords.append("高锰酸钾")
        if "高锰酸钾制氧气" not in keywords:
            keywords.append("高锰酸钾制氧气")
    if "电解质" in q and "电解质" not in keywords:
        keywords.append("电解质")
    if "氧化还原反应" in q and "氧化还原反应" not in keywords:
        keywords.append("氧化还原反应")
    if "氧化还原" in q and "氧化还原反应" not in keywords:
        keywords.append("氧化还原反应")
    if "中和反应" in q and "中和反应" not in keywords:
        keywords.append("中和反应")
    if "中和" in q and "中和反应" not in keywords:
        keywords.append("中和反应")
    if ("物质的量" in q or "摩尔" in q or "mol" in q) and "物质的量" not in keywords:
        keywords.append("物质的量")
    if "酸碱指示剂" in q and "酸碱指示剂" not in keywords:
        keywords.append("酸碱指示剂")
    if ("溶液" in q or "溶解度" in q or "饱和溶液" in q) and "溶液" not in keywords:
        keywords.append("溶液")
    if "氧气" in q and "氧气" not in keywords:
        keywords.append("氧气")
    if "制氧气" in q and "实验室制氧气" not in keywords:
        keywords.append("实验室制氧气")
        if "氧气" not in keywords:
            keywords.append("氧气")
    if "二氧化碳" in q and "二氧化碳" not in keywords:
        keywords.append("二氧化碳")
    if "制二氧化碳" in q and "实验室制二氧化碳" not in keywords:
        keywords.append("实验室制二氧化碳")
        if "二氧化碳" not in keywords:
            keywords.append("二氧化碳")
    if "金属活动性顺序" in q and "金属活动性顺序" not in keywords:
        keywords.append("金属活动性顺序")
    if "空气" in q and "空气" not in keywords:
        keywords.append("空气")

    # 若未识别到任何主题，则用原始问题作为检索关键词
    if not keywords:
        keywords.append(q)

    # 去重保持顺序
    seen = set()
    deduped: List[str] = []
    for k in keywords:
        if k not in seen:
            seen.add(k)
            deduped.append(k)
    return deduped


def _expand_kg_terms(base_keywords: List[str]) -> List[str]:
    """根据主题配置扩展知识图谱检索词"""
    terms: List[str] = []
    for kw in base_keywords:
        expanded = _TOPIC_KG_EXPANSIONS.get(kw, [kw])
        for t in expanded:
            if t not in terms:
                terms.append(t)
    return terms


def analyze_question(text: str) -> Dict[str, Any]:
    """将学生的自然语言问题解析为结构化信息

    返回内容示例：
    {
        "clean_text": "为啥高锰酸钾制氧要塞棉花",
        "type": "experiment",
        "keywords": ["高锰酸钾", "高锰酸钾制氧气"],
        "kg_terms": ["高锰酸钾制氧气", "高锰酸钾"]
    }
    """
    q = (text or "").strip()
    q = q.replace("？", "?").replace("！", "!").replace("。", ".")

    q_type = _guess_question_type(q)
    base_keywords = _extract_topic_keywords(q)
    kg_terms = _expand_kg_terms(base_keywords)

    return {
        "clean_text": q,
        "type": q_type.value,
        "keywords": base_keywords,
        "kg_terms": kg_terms,
    }