app.py

"""知识图谱学习助手 — Streamlit 前端"""

import streamlit as st
import os
import tempfile
from state import AppState
from kg_engine import build_graph_from_file
from quiz_engine import generate_questions, grade_answer, get_today_review, get_weakness_report


st.set_page_config(page_title="知识图谱学习助手", page_icon="🧠", layout="wide")

# ─── 初始化状态 ───
state = AppState()
state.load()

# 会话状态
if "current_questions" not in st.session_state:
    st.session_state.current_questions = []
if "current_idx" not in st.session_state:
    st.session_state.current_idx = 0
if "show_result" not in st.session_state:
    st.session_state.show_result = {}


# ─── 侧边栏 ───
with st.sidebar:
    st.title("🧠 知识图谱学习助手")
    st.caption("基于 DeepSeek + SM-2 的智能学习系统")
    st.divider()
    stats = state.get_stats()
    st.metric("概念数", stats["concepts"])
    st.metric("关系数", stats["relations"])
    st.metric("题目数", stats["questions"])
    st.metric("答题记录", stats["records"])
    if stats["records"] > 0:
        st.metric("正确率", stats["accuracy"])

    st.divider()
    if st.button("🗑️ 清空所有数据", type="secondary", use_container_width=True):
        state.clear()
        state.save()
        st.session_state.current_questions = []
        st.session_state.current_idx = 0
        st.session_state.show_result = {}
        st.rerun()


# ─── 主区域: 四个 Tab ───
tab1, tab2, tab3, tab4 = st.tabs(["📤 上传笔记", "🕸️ 知识图谱", "📝 答题模式", "📊 错题本"])

# ─── Tab 1: 上传笔记 ───
with tab1:
    st.header("上传学习笔记")
    st.caption("支持 PDF、Markdown、TXT 格式。AI 将自动抽取知识概念并构建图谱。")

    uploaded_file = st.file_uploader("拖拽文件到此处", type=["pdf", "md", "txt"], key="uploader")

    if uploaded_file:
        # 保存到临时文件
        suffix = os.path.splitext(uploaded_file.name)[1]
        with tempfile.NamedTemporaryFile(delete=False, suffix=suffix) as tmp:
            tmp.write(uploaded_file.getvalue())
            tmp_path = tmp.name

        if st.button("🚀 开始抽取知识图谱", type="primary", use_container_width=True):
            with st.spinner("AI 正在分析文档，抽取概念和关系..."):
                result = build_graph_from_file(tmp_path)

            if "error" in result:
                st.error(result["error"])
            else:
                st.success(f"抽取完成！新增 {result['new_concepts']} 个概念，总计 {result['concepts']} 个概念、{result['relations']} 条关系。")
                st.balloons()

        os.unlink(tmp_path)

    # 显示已有概念列表
    if state.concepts:
        st.divider()
        st.subheader(f"已收录概念（{len(state.concepts)}）")
        for c in list(state.concepts.values())[:20]:
            with st.expander(f"{c.name}  [{c.category}] 难度:{'⭐'*c.difficulty}"):
                st.write(c.description)
                if c.related_ids:
                    related = [state.concepts[rid].name for rid in c.related_ids if rid in state.concepts]
                    st.caption(f"关联: {'、'.join(related[:6])}")
    else:
        st.info("还没有概念数据，请先上传笔记文件。")


# ─── Tab 2: 知识图谱 ───
with tab2:
    st.header("知识图谱")

    if not state.concepts:
        st.info("图谱为空，请先到「上传笔记」页面添加学习资料。")
    else:
        # 筛选器
        col1, col2 = st.columns(2)
        with col1:
            categories = list(set(c.category for c in state.concepts.values()))
            selected_cats = st.multiselect("筛选分类", categories, default=categories, key="graph_filter")
        with col2:
            difficulty_range = st.slider("难度范围", 1, 5, (1, 5), key="diff_filter")

        # 构建PyVis图
        graph_data = state.get_graph_data()
        filtered_nodes = [
            n for n in graph_data["nodes"]
            if n["group"] in selected_cats and difficulty_range[0] <= n["difficulty"] <= difficulty_range[1]
        ]
        filtered_ids = {n["id"] for n in filtered_nodes}
        filtered_edges = [
            e for e in graph_data["edges"]
            if e["from"] in filtered_ids and e["to"] in filtered_ids
        ]

        if not filtered_nodes:
            st.warning("当前筛选条件下没有匹配的概念。")
        else:
            # 使用 networkx + pyvis 渲染
            try:
                from pyvis.network import Network
                import networkx as nx

                net = Network(height="550px", width="100%", bgcolor="#ffffff", font_color="#333333")
                color_map = {
                    "统计学": "#FF6B6B", "机器学习": "#4ECDC4", "Python": "#45B7D1",
                    "数据库": "#96CEB4", "业务分析": "#FFEAA7", "未分类": "#DDA0DD",
                }

                for n in filtered_nodes:
                    color = color_map.get(n["group"], "#DDA0DD")
                    net.add_node(
                        n["id"], label=n["label"], title=n["title"],
                        color=color, size=max(15, n["value"] * 8),
                    )
                for e in filtered_edges:
                    net.add_edge(e["from"], e["to"], title=e["title"], label=e["label"])

                net.set_options("""
                {
                  "physics": {
                    "barnesHut": {"gravitationalConstant": -3000, "springLength": 200},
                    "minVelocity": 0.75
                  },
                  "edges": {"smooth": {"type": "curvedCW"}, "arrows": {"to": {"enabled": true}}}
                }
                """)

                net.save_graph("data/graph.html")
                with open("data/graph.html", "r", encoding="utf-8") as f:
                    st.components.v1.html(f.read(), height=550)

            except ImportError:
                st.warning("需要安装 pyvis 和 networkx: pip install pyvis networkx")

        # 概念列表
        st.divider()
        st.subheader("概念详情")
        for c in list(state.concepts.values())[:30]:
            if c.category in selected_cats and difficulty_range[0] <= c.difficulty <= difficulty_range[1]:
                with st.expander(f"📌 {c.name} [{c.category}] {'⭐'*c.difficulty}"):
                    st.write(c.description)
                    st.caption(f"来源: {c.source_file}")


# ─── Tab 3: 答题模式 ───
with tab3:
    st.header("答题模式")

    if not state.concepts:
        st.info("请先上传笔记构建知识图谱。")
    else:
        # 选题范围
        col1, col2, col3 = st.columns(3)
        with col1:
            cats = list(set(c.category for c in state.concepts.values()))
            quiz_cats = st.multiselect("考察分类", cats, default=cats, key="quiz_cats")
        with col2:
            count = st.number_input("题目数量", 1, 10, 5)
        with col3:
            q_type = st.selectbox("题型", ["mixed", "choice", "short_answer"], format_func=lambda x: {"mixed": "混合", "choice": "选择题", "short_answer": "简答题"}[x])

        if st.button("🎲 生成题目", type="primary", use_container_width=True):
            target_ids = [c.id for c in state.concepts.values() if c.category in quiz_cats]
            if target_ids:
                with st.spinner("AI 正在出题..."):
                    st.session_state.current_questions = generate_questions(target_ids, count, q_type)
                st.session_state.current_idx = 0
                st.session_state.show_result = {}
                st.rerun()

        # 答题区
        questions = st.session_state.current_questions
        if questions:
            idx = st.session_state.current_idx
            if idx < len(questions):
                q = questions[idx]
                st.divider()
                type_badge = "🔤 选择题" if q.q_type == "choice" else "✍️ 简答题"
                st.subheader(f"第 {idx+1}/{len(questions)} 题  {type_badge}  难度:{'⭐'*q.difficulty}")

                # 显示关联知识点
                concept_names = [state.concepts[cid].name for cid in q.concept_ids if cid in state.concepts]
                st.caption(f"知识点: {'、'.join(concept_names)}")

                st.markdown(f"**{q.question}**")

                # 答题输入
                result_key = f"result_{idx}"
                if result_key not in st.session_state.show_result:
                    if q.q_type == "choice":
                        user_answer = st.radio("请选择:", q.options, key=f"choice_{idx}")
                    else:
                        user_answer = st.text_area("请输入你的答案:", key=f"short_{idx}", height=100)

                    col_btn1, col_btn2 = st.columns([1, 4])
                    with col_btn1:
                        if st.button("✅ 提交", type="primary", key=f"submit_{idx}"):
                            with st.spinner("AI 正在批改..."):
                                record = grade_answer(q, user_answer)
                            st.session_state.show_result[result_key] = record
                            st.rerun()
                else:
                    # 显示结果
                    record = st.session_state.show_result[result_key]
                    if record.is_correct:
                        st.success(f"✅ 正确！得分: {record.score}/5")
                    else:
                        st.error(f"❌ 需要加强。得分: {record.score}/5")

                    st.info(f"**正确答案:** {q.correct_answer}")
                    st.markdown(f"**解析:** {q.explanation}")
                    st.caption(f"**AI 反馈:** {record.feedback}")
                    st.caption(f"下次复习: {record.next_review}（间隔 {record.sm2_interval} 天）")

                # 导航按钮
                col_prev, col_next = st.columns(2)
                with col_prev:
                    if idx > 0 and st.button("⬅️ 上一题", key=f"prev_{idx}"):
                        st.session_state.current_idx -= 1
                        st.rerun()
                with col_next:
                    if idx < len(questions) - 1 and st.button("下一题 ➡️", key=f"next_{idx}"):
                        st.session_state.current_idx += 1
                        st.rerun()
            else:
                st.success("🎉 全部题目已完成！")
                if st.button("再来一组", type="primary"):
                    st.session_state.current_questions = []
                    st.session_state.current_idx = 0
                    st.session_state.show_result = {}
                    st.rerun()


# ─── Tab 4: 错题本 ───
with tab4:
    st.header("错题本 & 薄弱点分析")

    if not state.records:
        st.info("还没有答题记录，请先到「答题模式」做题。")
    else:
        # 薄弱知识点
        st.subheader("📉 薄弱知识点 Top 10")
        weakness = get_weakness_report(10)
        if weakness:
            for concept, rate in weakness:
                st.progress(rate, text=f"{concept.name} [{concept.category}] — 正确率 {rate:.0%}")
        else:
            st.success("所有知识点掌握良好！")

        # 今日待复习
        st.divider()
        st.subheader("📅 今日待复习")
        due_items = get_today_review()
        if due_items:
            for record, question in due_items[:10]:
                with st.expander(f"📌 {question.question[:80]}...（上次得分:{record.score}/5，间隔:{record.sm2_interval}天）"):
                    st.markdown(f"**上次你的答案:** {record.user_answer}")
                    st.markdown(f"**正确答案:** {question.correct_answer}")
                    st.markdown(f"**解析:** {question.explanation}")
                    st.caption(f"**反馈:** {record.feedback}")
        else:
            st.success("🎉 今天没有需要复习的题目！")

        # 历史记录
        st.divider()
        st.subheader("📋 全部答题记录")
        for r in reversed(state.records[-20:]):
            q = state.questions.get(r.question_id)
            if q:
                icon = "✅" if r.is_correct else "❌"
                st.caption(f"{icon} {q.question[:60]}... | 得分:{r.score}/5 | {r.reviewed_at} | 下次:{r.next_review}")