Files
chatgpt-on-wechat/agent/chat/session_service.py
2026-04-14 22:58:25 +08:00

213 lines
8.2 KiB
Python

"""
SessionService - Manages multi-session lifecycle for both web channel and cloud client.
Provides a unified interface for listing, deleting, renaming, clearing context,
and generating AI titles for conversation sessions. Backed by ConversationStore
(SQLite) and AgentBridge (in-memory agent instances).
"""
import re
from typing import Optional
from common.log import logger
def generate_session_title(user_message: str, assistant_reply: str = "") -> str:
"""
Generate a short session title by calling the current bot's reply_text.
Falls back to a truncated user message if the LLM call fails.
"""
fallback = user_message[:50].split("\n")[0].strip() or "New Chat"
try:
from bridge.bridge import Bridge
from models.session_manager import Session
bot = Bridge().get_bot("chat")
prompt_parts = [f"User: {user_message[:300]}"]
if assistant_reply:
prompt_parts.append(f"Assistant: {assistant_reply[:300]}")
session = Session("__title_gen__", system_prompt="")
session.messages = [
{"role": "user", "content": (
"Generate a very short title (max 15 characters for Chinese, max 6 words for English) "
"summarizing this conversation. Return ONLY the title text, nothing else.\n\n"
+ "\n".join(prompt_parts)
)}
]
result = bot.reply_text(session)
raw = (result.get("content") or "").strip()
title = re.sub(r'<think>.*?</think>', '', raw, flags=re.DOTALL).strip().strip('"\'')
logger.info(f"[SessionService] Title generation result: '{title}' (len={len(title)})")
if title and len(title) <= 50:
return title
except Exception as e:
logger.warning(f"[SessionService] Title generation failed: {e}")
return fallback
class SessionService:
"""
High-level service for session lifecycle management.
Usage:
svc = SessionService()
result = svc.dispatch("list", {"channel_type": "web", "page": 1})
"""
def _get_store(self):
from agent.memory import get_conversation_store
return get_conversation_store()
def _remove_agent(self, session_id: str):
"""Remove the in-memory Agent instance for a session if it exists."""
try:
from bridge.bridge import Bridge
ab = Bridge().get_agent_bridge()
if session_id in ab.agents:
del ab.agents[session_id]
logger.info(f"[SessionService] Removed agent instance: {session_id}")
except Exception:
pass
@staticmethod
def _normalize_sid(session_id: str) -> str:
if session_id and not session_id.startswith("session_"):
return f"session_{session_id}"
return session_id
# ------------------------------------------------------------------
# actions
# ------------------------------------------------------------------
def list_sessions(self, channel_type: Optional[str] = None,
page: int = 1, page_size: int = 50) -> dict:
store = self._get_store()
return store.list_sessions(
channel_type=channel_type,
page=page,
page_size=page_size,
)
def delete_session(self, session_id: str) -> None:
if not session_id:
raise ValueError("session_id required")
session_id = self._normalize_sid(session_id)
store = self._get_store()
store.clear_session(session_id)
self._remove_agent(session_id)
logger.info(f"[SessionService] Session deleted: {session_id}")
def rename_session(self, session_id: str, title: str) -> None:
if not session_id:
raise ValueError("session_id required")
if not title:
raise ValueError("title required")
session_id = self._normalize_sid(session_id)
store = self._get_store()
found = store.rename_session(session_id, title)
if not found:
raise ValueError("session not found")
def clear_context(self, session_id: str) -> int:
"""
Set context boundary. Returns the new context_start_seq value.
"""
if not session_id:
raise ValueError("session_id required")
session_id = self._normalize_sid(session_id)
store = self._get_store()
new_seq = store.clear_context(session_id)
self._remove_agent(session_id)
return new_seq
def gen_title(self, session_id: str, user_message: str,
assistant_reply: str = "") -> str:
"""
Generate an AI title and persist it. Returns the generated title.
"""
if not session_id:
raise ValueError("session_id required")
if not user_message:
raise ValueError("user_message required")
session_id = self._normalize_sid(session_id)
title = generate_session_title(user_message, assistant_reply)
store = self._get_store()
updated = store.rename_session(session_id, title)
logger.info(f"[SessionService] Title set: sid={session_id}, "
f"title='{title}', db_updated={updated}")
return title
# ------------------------------------------------------------------
# dispatch — single entry point for protocol messages
# ------------------------------------------------------------------
def dispatch(self, action: str, payload: Optional[dict] = None) -> dict:
"""
Dispatch a session management action and return a protocol-compatible
response dict.
Action names use a ``*_session`` / session-prefixed convention so they
can coexist with history actions (e.g. ``query``) on the same HISTORY
message channel without ambiguity.
Supported actions:
- list_sessions: list sessions with pagination
- delete_session: delete a session
- rename_session: rename a session title
- clear_context: set context boundary
- generate_title: AI-generate a session title
:param action: one of the above action names
:param payload: action-specific payload
:return: dict with action, code, message, payload
"""
payload = payload or {}
try:
if action == "list_sessions":
result = self.list_sessions(
channel_type=payload.get("channel_type"),
page=int(payload.get("page", 1)),
page_size=int(payload.get("page_size", 50)),
)
return {"action": action, "code": 200, "message": "success", "payload": result}
elif action == "delete_session":
self.delete_session(payload.get("session_id", ""))
return {"action": action, "code": 200, "message": "success", "payload": None}
elif action == "rename_session":
self.rename_session(
payload.get("session_id", ""),
payload.get("title", "").strip(),
)
return {"action": action, "code": 200, "message": "success", "payload": None}
elif action == "clear_context":
new_seq = self.clear_context(payload.get("session_id", ""))
return {"action": action, "code": 200, "message": "success",
"payload": {"context_start_seq": new_seq}}
elif action == "generate_title":
title = self.gen_title(
payload.get("session_id", ""),
payload.get("user_message", ""),
payload.get("assistant_reply", ""),
)
return {"action": action, "code": 200, "message": "success",
"payload": {"title": title}}
else:
return {"action": action, "code": 400,
"message": f"unknown action: {action}", "payload": None}
except ValueError as e:
return {"action": action, "code": 400, "message": str(e), "payload": None}
except Exception as e:
logger.error(f"[SessionService] dispatch error: action={action}, error={e}")
return {"action": action, "code": 500, "message": str(e), "payload": None}