Files
deer-flow/backend/app/gateway/routers/suggestions.py
2026-03-22 19:59:54 +08:00

133 lines
4.6 KiB
Python

import json
import logging
from fastapi import APIRouter
from pydantic import BaseModel, Field
from deerflow.models import create_chat_model
logger = logging.getLogger(__name__)
router = APIRouter(prefix="/api", tags=["suggestions"])
class SuggestionMessage(BaseModel):
role: str = Field(..., description="Message role: user|assistant")
content: str = Field(..., description="Message content as plain text")
class SuggestionsRequest(BaseModel):
messages: list[SuggestionMessage] = Field(..., description="Recent conversation messages")
n: int = Field(default=3, ge=1, le=5, description="Number of suggestions to generate")
model_name: str | None = Field(default=None, description="Optional model override")
class SuggestionsResponse(BaseModel):
suggestions: list[str] = Field(default_factory=list, description="Suggested follow-up questions")
def _strip_markdown_code_fence(text: str) -> str:
stripped = text.strip()
if not stripped.startswith("```"):
return stripped
lines = stripped.splitlines()
if len(lines) >= 3 and lines[0].startswith("```") and lines[-1].startswith("```"):
return "\n".join(lines[1:-1]).strip()
return stripped
def _parse_json_string_list(text: str) -> list[str] | None:
candidate = _strip_markdown_code_fence(text)
start = candidate.find("[")
end = candidate.rfind("]")
if start == -1 or end == -1 or end <= start:
return None
candidate = candidate[start : end + 1]
try:
data = json.loads(candidate)
except Exception:
return None
if not isinstance(data, list):
return None
out: list[str] = []
for item in data:
if not isinstance(item, str):
continue
s = item.strip()
if not s:
continue
out.append(s)
return out
def _extract_response_text(content: object) -> str:
if isinstance(content, str):
return content
if isinstance(content, list):
parts: list[str] = []
for block in content:
if isinstance(block, str):
parts.append(block)
elif isinstance(block, dict) and block.get("type") in {"text", "output_text"}:
text = block.get("text")
if isinstance(text, str):
parts.append(text)
return "\n".join(parts) if parts else ""
if content is None:
return ""
return str(content)
def _format_conversation(messages: list[SuggestionMessage]) -> str:
parts: list[str] = []
for m in messages:
role = m.role.strip().lower()
if role in ("user", "human"):
parts.append(f"User: {m.content.strip()}")
elif role in ("assistant", "ai"):
parts.append(f"Assistant: {m.content.strip()}")
else:
parts.append(f"{m.role}: {m.content.strip()}")
return "\n".join(parts).strip()
@router.post(
"/threads/{thread_id}/suggestions",
response_model=SuggestionsResponse,
summary="Generate Follow-up Questions",
description="Generate short follow-up questions a user might ask next, based on recent conversation context.",
)
async def generate_suggestions(thread_id: str, request: SuggestionsRequest) -> SuggestionsResponse:
if not request.messages:
return SuggestionsResponse(suggestions=[])
n = request.n
conversation = _format_conversation(request.messages)
if not conversation:
return SuggestionsResponse(suggestions=[])
prompt = (
"You are generating follow-up questions to help the user continue the conversation.\n"
f"Based on the conversation below, produce EXACTLY {n} short questions the user might ask next.\n"
"Requirements:\n"
"- Questions must be relevant to the conversation.\n"
"- Questions must be written in the same language as the user.\n"
"- Keep each question concise (ideally <= 20 words / <= 40 Chinese characters).\n"
"- Do NOT include numbering, markdown, or any extra text.\n"
"- Output MUST be a JSON array of strings only.\n\n"
"Conversation:\n"
f"{conversation}\n"
)
try:
model = create_chat_model(name=request.model_name, thinking_enabled=False)
response = model.invoke(prompt)
raw = _extract_response_text(response.content)
suggestions = _parse_json_string_list(raw) or []
cleaned = [s.replace("\n", " ").strip() for s in suggestions if s.strip()]
cleaned = cleaned[:n]
return SuggestionsResponse(suggestions=cleaned)
except Exception as exc:
logger.exception("Failed to generate suggestions: thread_id=%s err=%s", thread_id, exc)
return SuggestionsResponse(suggestions=[])