feat: 客服对话支持寒暄回复与跑题拒答

问候不再写入槽位；明显无关问题直接拒绝，知识库未命中时明确说明无法回答，并继续合理追问。

Co-authored-by: haijd <haijd@163.com>

engine/app/intent.py

@@ -0,0 +1,116 @@
+from __future__ import annotations
+
+import re
+
+# 寒暄：不写槽、先回问候再追问
+_GREETING_RE = re.compile(
+    r"^\s*(hi|hello|hey|hola|yo|你好|您好|哈喽|嗨|早上好|上午好|中午好|下午好|晚上好|早|在吗|在不在)[\s!！.。~～？?]*$",
+    re.I,
+)
+
+# 跳过/暂无类有效回答
+_SKIP_RE = re.compile(r"暂无|没有|无|不清楚|不确定|随便|都可以|未知|n/?a|none|no\b", re.I)
+
+# 鲜境业务相关词：冷链温控 / 官网产品线
+_DOMAIN_RE = re.compile(
+    r"冷链|冷库|仓储|仓库|运输|配送|保温|冷冻|冷藏|温控|温度|湿度|"
+    r"药品|疫苗|生鲜|实验室|产线|户外|监测|告警|报警|"
+    r"TagPlus|BlueTag|GAEA|Fresh\s*Tag|USB|PDF|蓝牙|网关|记录仪|"
+    r"不开箱|行程|温区|WiFi|4G|LAN|API|方案|产品|报价|选型|"
+    r"实时|读数|报告|传感器|物联网|物联|预算|网络|对接|系统|次数|可重复",
+    re.I,
+)
+
+# 明显跑题话题
+_OFFTOPIC_RE = re.compile(
+    r"天气|气温|下雨|新闻|股票|基金|彩票|足球|篮球|电影|电视剧|游戏|"
+    r"笑话|段子|星座|运势|做饭|菜谱|旅游|机票|酒店|恋爱|八卦|"
+    r"政治|选举|战争|加密货币|比特币|chatgpt|写诗|作文|数学题|"
+    r"编程作业|leetcode|今天吃什么",
+    re.I,
+)
+
+_QUESTION_RE = re.compile(r"[?？]|什么是|怎么|如何|能否|可以吗|多少|哪[个些]|是否|介绍一下|有没有")
+
+
+def is_greeting(text: str) -> bool:
+    return bool(_GREETING_RE.match((text or "").strip()))
+
+
+def is_skip_answer(text: str) -> bool:
+    t = (text or "").strip()
+    if not t:
+        return False
+    if _SKIP_RE.fullmatch(t):
+        return True
+    return t in {"没有要求", "无要求", "没什么", "先不确定"}
+
+
+def is_domain_related(text: str) -> bool:
+    return bool(_DOMAIN_RE.search(text or ""))
+
+
+def looks_like_question(text: str) -> bool:
+    return bool(_QUESTION_RE.search(text or ""))
+
+
+def has_offtopic_topic(text: str) -> bool:
+    return bool(_OFFTOPIC_RE.search(text or ""))
+
+
+def looks_off_topic(text: str) -> bool:
+    """明显与冷链方案无关的输入；寒暄单独处理，不算跑题。"""
+    t = (text or "").strip()
+    if not t or is_greeting(t) or is_skip_answer(t):
+        return False
+    if is_domain_related(t):
+        return False
+    if _OFFTOPIC_RE.search(t):
+        return True
+    # 纯英文闲聊 / 极短无意义且不像在答槽
+    if re.fullmatch(r"[a-zA-Z\s!.?~]{1,40}", t) and not is_domain_related(t):
+        lower = t.lower()
+        if any(w in lower for w in ("hello", "hi", "hey", "thanks", "bye", "ok", "test")):
+            return False  # greeting/ack 另判
+        if looks_like_question(t):
+            return True
+    # 较长文本却无任何业务词 → 视为跑题
+    if len(t) >= 8 and not is_domain_related(t) and looks_like_question(t):
+        return True
+    if len(t) >= 16 and not is_domain_related(t):
+        return True
+    return False
+
+
+def should_write_slot(text: str) -> bool:
+    """是否允许本轮用户话写入槽位。"""
+    t = (text or "").strip()
+    if not t or is_greeting(t):
+        return False
+    if looks_off_topic(t):
+        return False
+    return True
+
+
+def greeting_reply(next_prompt: str | None) -> str:
+    base = "你好！我是鲜境方案客服，可以帮您梳理冷链温控场景并匹配官网产品组合。"
+    if next_prompt:
+        return f"{base}\n\n{next_prompt}"
+    return f"{base}\n\n您可以直接描述场景，例如：「冷库仓储，要实时告警」。"
+
+
+def refuse_reply(reason: str = "off_topic", next_prompt: str | None = None) -> str:
+    if reason == "kb_miss":
+        msg = (
+            "抱歉，我无法回答这个问题。"
+            "当前知识库里没有足够相关依据，请换一个与鲜境冷链温控产品/场景相关的问题，"
+            "或描述您的应用现场，我再帮您追问选型。"
+        )
+    else:
+        msg = (
+            "抱歉，我无法回答这类问题。"
+            "我主要协助鲜境物联的冷链温控方案咨询（运输记录、蓝牙读数、仓储网关等）。"
+        )
+    if next_prompt:
+        return f"{msg}\n\n我们继续：{next_prompt}"
+    return msg

engine/app/retrieval.py

@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+import re
 from typing import Any
 
 from .config_loader import business_config
@@ -24,6 +25,67 @@ def retrieve_for_scheme(slots: dict[str, str], bundle: list[str]) -> RetrievalRe
         return RetrievalResult([], "ragflow", warning=str(exc))
 
 
+def retrieve_question(question: str, *, page_size: int = 3, min_score: float = 0.22) -> RetrievalResult:
+    """自由问答检索；分数过低视为知识库未命中。"""
+    backend = (settings.retrieval_backend or "ragflow").lower()
+    q = (question or "").strip()
+    if not q:
+        return RetrievalResult([], backend or "none", warning="empty_query")
+    if backend == "mock":
+        return _retrieve_mock_question(q, min_score=min_score)
+    try:
+        client = RagflowClient()
+        dataset_ids = [item.strip() for item in settings.ragflow_dataset_ids.split(",") if item.strip()]
+        raw = client.retrieve(q, dataset_ids, page_size=page_size)
+        chunks = []
+        for index, item in enumerate(raw[:page_size]):
+            if not isinstance(item, dict):
+                continue
+            score = item.get("similarity")
+            try:
+                score_f = float(score) if score is not None else 0.0
+            except (TypeError, ValueError):
+                score_f = 0.0
+            if score_f < min_score:
+                continue
+            chunks.append(
+                {
+                    "id": item.get("id") or f"rf-q-{index}",
+                    "title": item.get("document_keyword")
+                    or item.get("document_name")
+                    or item.get("docnm_kwd")
+                    or "知识片段",
+                    "content": item.get("content") or item.get("content_with_weight") or "",
+                    "score": score_f,
+                }
+            )
+        warning = "" if chunks else "知识库未召回到足够相关的内容"
+        return RetrievalResult(chunks, "ragflow", warning=warning)
+    except RagflowError as exc:
+        return RetrievalResult([], "ragflow", warning=str(exc))
+
+
+def _retrieve_mock_question(question: str, *, min_score: float = 0.22) -> RetrievalResult:
+    picked: list[dict[str, Any]] = []
+    for chunk in business_config.chunks:
+        blob = f"{chunk.get('title', '')} {chunk.get('content', '')} {' '.join(chunk.get('tags') or [])}"
+        hits = sum(1 for token in re_split_tokens(question) if token and token in blob)
+        if hits:
+            score = min(0.9, 0.2 + 0.15 * hits)
+            if score >= min_score:
+                item = dict(chunk)
+                item["score"] = score
+                picked.append(item)
+        if len(picked) >= 3:
+            break
+    warning = "" if picked else "知识库未召回到足够相关的内容"
+    return RetrievalResult(picked, "mock", warning=warning)
+
+
+def re_split_tokens(text: str) -> list[str]:
+    return [t for t in re.split(r"[\s,，。；;？?！!/|]+", text) if len(t) >= 2]
+
+
 def _retrieve_mock(slots: dict[str, str], bundle: list[str]) -> RetrievalResult:
     chunks = business_config.chunks
     picked: list[dict[str, Any]] = []

engine/app/scheme_engine.py

@@ -4,7 +4,17 @@ from typing import Any
 
 from .config_loader import business_config
 from .decision import evaluate_tree
-from .retrieval import retrieve_for_scheme
+from .intent import (
+    greeting_reply,
+    has_offtopic_topic,
+    is_domain_related,
+    is_greeting,
+    looks_like_question,
+    looks_off_topic,
+    refuse_reply,
+    should_write_slot,
+)
+from .retrieval import retrieve_for_scheme, retrieve_question
 from .session_store import (
     Session,
     looks_like_handoff,
@@ -25,34 +35,79 @@ def handle_message(session_id: str, message: str) -> dict[str, Any]:
 
     text = (message or "").strip()
     session.messages.append({"role": "user", "content": text})
+    nxt = next_slot_prompt(business_config.slots, session.slots)
+    next_prompt = nxt["prompt"] if nxt else None
 
     if looks_like_handoff(text, business_config.handoff_phrases):
         session.phase = "handoff"
         reply = "已为您标记转人工。请留下称呼与联系方式，销售同事会跟进。（原型：仅记录意图，未接 Chatwoot）"
         return _finish(session, reply, need_handoff=True)
 
-    # fill slots while collecting
-    if session.phase in ("collecting", "scheme_ready"):
+    # 寒暄：回问候 + 合理追问，绝不把 hello 写进槽位
+    if is_greeting(text):
+        return _finish(session, greeting_reply(next_prompt), asking_slot=nxt["id"] if nxt else None)
+
+    # 明显跑题：拒答并拉回当前追问
+    if looks_off_topic(text):
+        return _finish(
+            session,
+            refuse_reply("off_topic", next_prompt),
+            asking_slot=nxt["id"] if nxt else None,
+        )
+
+    # 业务相关自由提问：先查知识库；没命中则拒答，不强行灌槽
+    # 同时夹带明显跑题话题（如「记录仪能炒股吗」）→ 直接拒答
+    if looks_like_question(text) and is_domain_related(text):
+        if has_offtopic_topic(text):
+            return _finish(
+                session,
+                refuse_reply("off_topic", next_prompt),
+                asking_slot=nxt["id"] if nxt else None,
+            )
+        qa = retrieve_question(text)
+        if not qa.chunks:
+            return _finish(
+                session,
+                refuse_reply("kb_miss", next_prompt),
+                asking_slot=nxt["id"] if nxt else None,
+            )
+        lines = ["根据知识库，简要说明如下：", ""]
+        for citation in qa.chunks[:3]:
+            lines.append(f"- {citation.get('title')}：{citation.get('content')}")
+        if next_prompt and session.phase == "collecting":
+            lines.append("")
+            lines.append(f"若要继续匹配方案：{next_prompt}")
+        return _finish(session, "\n".join(lines), asking_slot=nxt["id"] if nxt else None)
+
+    # 正常收集槽位
+    if session.phase in ("collecting", "scheme_ready") and should_write_slot(text):
         session.slots = naive_fill_slots(text, business_config.slots, session.slots)
 
     nxt = next_slot_prompt(business_config.slots, session.slots)
     if nxt and session.phase == "collecting":
-        # first turn with empty slots: greet + first question
-        if len(session.messages) == 1 and not any(session.slots.values()):
-            # put first user utterance into first slot if they already answered something
-            session.slots = naive_fill_slots(text, business_config.slots, session.slots)
-            nxt = next_slot_prompt(business_config.slots, session.slots)
-        if nxt:
-            reply = nxt["prompt"]
-            return _finish(session, reply, asking_slot=nxt["id"])
+        reply = nxt["prompt"]
+        return _finish(session, reply, asking_slot=nxt["id"])
 
-    # all required (+ optional asked or filled) → scheme
+    # 槽位齐了 → 出方案；知识库完全无依据时明确说明无法背书
     decision = evaluate_tree(business_config.rules, session.slots)
     confidence = float(decision.get("confidence") or 0)
     need_handoff = bool(decision.get("handoff")) or confidence < business_config.handoff_confidence_below
     bundle = list(decision.get("product_bundle") or [])
     retrieval = retrieve_for_scheme(session.slots, bundle)
 
+    # 槽位内容本身不像业务需求，且检索也空 → 拒答
+    slot_blob = " ".join(str(v) for v in session.slots.values() if v)
+    if not is_domain_related(slot_blob) and not retrieval.chunks:
+        reply = refuse_reply("kb_miss", None)
+        session.phase = "collecting"
+        # 清空无效槽，避免一直卡在坏状态
+        session.slots = {}
+        first = next_slot_prompt(business_config.slots, session.slots)
+        if first:
+            reply = refuse_reply("off_topic", first["prompt"])
+            return _finish(session, reply, asking_slot=first["id"])
+        return _finish(session, reply)
+
     scheme = {
         "tech_line": decision.get("tech_line"),
         "product_bundle": bundle,
@@ -93,7 +148,7 @@ def handle_message(session_id: str, message: str) -> dict[str, Any]:
             lines.append(f"- {citation['title']}：{citation['content']}")
     else:
         lines.append("")
-        lines.append("知识库未给出可引用片段，请勿把上述组合当成已确认报价。")
+        lines.append("知识库未给出可引用片段，请勿把上述组合当成已确认报价。若问题超出资料范围，我无法保证回答准确。")
     if need_handoff or retrieval.warning:
         lines.append("")
         lines.append("建议转人工确认后再发给客户。可在右侧留下称呼和电话。")

engine/app/session_store.py

@@ -48,9 +48,11 @@ def looks_like_handoff(text: str, phrases: list[str]) -> bool:
 
 def naive_fill_slots(message: str, slots_meta: list[dict[str, Any]], current: dict[str, str]) -> dict[str, str]:
     """每轮通常只推进一个槽：先做明确关键词，再把整句写入当前优先空槽。"""
+    from .intent import should_write_slot
+
     updated = dict(current)
     text = message.strip()
-    if not text:
+    if not text or not should_write_slot(text):
         return updated
 
     touched = False