377 lines
14 KiB
Python
377 lines
14 KiB
Python
"""
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FastAPI 后端 - 支持动态模型切换，使用 PostgreSQL 持久化记忆
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采用依赖注入模式，优雅管理资源生命周期
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"""
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import os
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from .config import DB_URI, BACKEND_PORT
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import uuid
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import json
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from contextlib import asynccontextmanager
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from typing import Optional
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from fastapi import FastAPI, HTTPException, WebSocket, WebSocketDisconnect, Depends, Request, Query
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from fastapi.middleware.cors import CORSMiddleware
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from fastapi.responses import StreamingResponse
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from pydantic import BaseModel
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from langgraph.checkpoint.postgres.aio import AsyncPostgresSaver
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from .agent.service import AIAgentService
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from .agent.history import ThreadHistoryService
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from .agent_subgraphs.common.human_review import (
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ReviewManager,
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InMemoryReviewStore,
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ReviewStatus,
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HumanReview
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)
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from .agent_subgraphs.contact.api_client import ContactAPIClient
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from .agent_subgraphs.dictionary.api_client import DictionaryAPIClient
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from .agent_subgraphs.news_analysis.api_client import NewsAPIClient
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from .db.init_db import init_subgraph_tables
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from .db.models import ContactRepository, DictionaryRepository, NewsRepository
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from .logger import info, error
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@asynccontextmanager
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async def lifespan(app: FastAPI):
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"""应用生命周期管理：创建并注入全局服务"""
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# 1. 创建数据库连接池并初始化表（仅 checkpointer）
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async with AsyncPostgresSaver.from_conn_string(DB_URI) as checkpointer:
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await checkpointer.setup()
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# 1.5 初始化子图表
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await init_subgraph_tables(checkpointer.conn)
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# 2. 构建 AI Agent 服务
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agent_service = AIAgentService(checkpointer)
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await agent_service.initialize()
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# 3. 创建历史查询服务（保持原有的 checkpointer 参数）
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history_service = ThreadHistoryService(checkpointer)
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# 3.5 创建子图 Repositories
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contact_repo = ContactRepository(checkpointer.conn)
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dictionary_repo = DictionaryRepository(checkpointer.conn)
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news_repo = NewsRepository(checkpointer.conn)
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# 3.6 创建子图 API 客户端（真实数据库模式）
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contact_api = ContactAPIClient(checkpointer.conn)
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dictionary_api = DictionaryAPIClient(word_repository=dictionary_repo)
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news_api = NewsAPIClient(news_repository=news_repo)
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# 4. 创建审核管理器
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review_manager = ReviewManager(InMemoryReviewStore())
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# 5. 将服务实例存入 app.state
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app.state.agent_service = agent_service
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app.state.history_service = history_service
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app.state.review_manager = review_manager
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app.state.contact_api = contact_api
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app.state.dictionary_api = dictionary_api
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app.state.news_api = news_api
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app.state.contact_repo = contact_repo
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app.state.dictionary_repo = dictionary_repo
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app.state.news_repo = news_repo
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# 应用运行中...
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yield
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# 6. 关闭时自动清理数据库连接（async with 负责）
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info("🛑 应用关闭，数据库连接池已释放")
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app = FastAPI(lifespan=lifespan)
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# CORS 中间件（允许前端跨域）
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app.add_middleware(
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CORSMiddleware,
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allow_origins=["*"],
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allow_credentials=True,
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allow_methods=["*"],
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allow_headers=["*"],
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)
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# ========== 健康检查端点 ==========
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@app.get("/health")
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async def health_check():
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"""健康检查端点，用于 Docker 和 CI/CD 监控"""
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return {"status": "ok", "service": "ai-agent-backend"}
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# ========== Pydantic 模型 ==========
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class ChatRequest(BaseModel):
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message: str
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thread_id: str | None = None
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model: str = "zhipu"
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user_id: str = "default_user"
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class ChatResponse(BaseModel):
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reply: str
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thread_id: str
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model_used: str
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input_tokens: int = 0
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output_tokens: int = 0
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total_tokens: int = 0
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elapsed_time: float = 0.0
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class ReviewActionRequest(BaseModel):
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review_id: str
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reviewer: str
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comment: str = ""
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modified_content: str = ""
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class ReviewResponse(BaseModel):
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review_id: str
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thread_id: str
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user_id: str
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status: str
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content_to_review: str
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review_comment: str = ""
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modified_content: str = ""
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created_at: str
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reviewed_at: Optional[str] = None
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# ========== 依赖注入函数 ==========
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def get_agent_service(request: Request) -> AIAgentService:
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"""从 app.state 中获取全局 AIAgentService 实例"""
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return request.app.state.agent_service
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def get_history_service(request: Request) -> ThreadHistoryService:
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"""从 app.state 中获取全局 ThreadHistoryService 实例"""
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return request.app.state.history_service
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def get_review_manager(request: Request) -> ReviewManager:
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"""从 app.state 中获取全局 ReviewManager 实例"""
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return request.app.state.review_manager
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# ========== HTTP 端点 ==========
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@app.post("/chat", response_model=ChatResponse)
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async def chat_endpoint(
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request: ChatRequest,
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agent_service: AIAgentService = Depends(get_agent_service)
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):
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"""同步对话接口，支持模型选择"""
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if not request.message:
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raise HTTPException(status_code=400, detail="message required")
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thread_id = request.thread_id or str(uuid.uuid4())
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result = await agent_service.process_message(
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request.message, thread_id, request.model, request.user_id
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)
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# 提取 token 统计信息
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token_usage = result.get("token_usage", {})
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input_tokens = token_usage.get('prompt_tokens', token_usage.get('input_tokens', 0))
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output_tokens = token_usage.get('completion_tokens', token_usage.get('output_tokens', 0))
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elapsed_time = result.get("elapsed_time", 0.0)
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actual_model = request.model if request.model in agent_service.graphs else next(iter(agent_service.graphs.keys()))
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return ChatResponse(
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reply=result["reply"],
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thread_id=thread_id,
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model_used=actual_model,
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input_tokens=input_tokens,
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output_tokens=output_tokens,
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total_tokens=input_tokens + output_tokens,
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elapsed_time=elapsed_time
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)
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# ========== 历史查询接口 ==========
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@app.get("/threads")
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async def list_threads(
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user_id: str = Query("default_user", description="用户 ID"),
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limit: int = Query(50, ge=1, le=200, description="返回数量限制"),
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history_service: ThreadHistoryService = Depends(get_history_service)
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):
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"""获取当前用户的对话历史列表"""
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threads = await history_service.get_user_threads(user_id, limit)
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return {"threads": threads}
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@app.get("/thread/{thread_id}/messages")
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async def get_thread_messages(
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thread_id: str,
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user_id: str = Query("default_user", description="用户 ID"),
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history_service: ThreadHistoryService = Depends(get_history_service)
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):
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"""获取指定线程的完整消息历史"""
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messages = await history_service.get_thread_messages(thread_id)
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return {"messages": messages}
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@app.get("/thread/{thread_id}/summary")
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async def get_thread_summary(
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thread_id: str,
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user_id: str = Query("default_user", description="用户 ID"),
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history_service: ThreadHistoryService = Depends(get_history_service)
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):
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"""获取指定线程的摘要信息"""
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summary = await history_service.get_thread_summary(thread_id)
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return summary
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# ========== 流式对话接口 ==========
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@app.post("/chat/stream")
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async def chat_stream_endpoint(
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request: ChatRequest,
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agent_service: AIAgentService = Depends(get_agent_service)
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):
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"""流式对话接口（SSE）"""
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if not request.message:
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raise HTTPException(status_code=400, detail="message required")
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thread_id = request.thread_id or str(uuid.uuid4())
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async def event_generator():
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try:
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async for chunk in agent_service.process_message_stream(
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request.message, thread_id, request.model, request.user_id
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):
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yield f"data: {json.dumps(chunk, ensure_ascii=False)}\n\n"
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yield "data: [DONE]\n\n"
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except Exception as e:
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error(f"流式响应异常: {e}")
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yield f"data: {json.dumps({'type': 'error', 'message': str(e)}, ensure_ascii=False)}\n\n"
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yield "data: [DONE]\n\n"
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return StreamingResponse(
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event_generator(),
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media_type="text/event-stream",
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headers={
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"Cache-Control": "no-cache",
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"Connection": "keep-alive",
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"X-Accel-Buffering": "no", # 禁用 Nginx 缓冲
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}
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)
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# ========== WebSocket 端点（可选） ==========
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@app.websocket("/ws")
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async def websocket_endpoint(
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websocket: WebSocket,
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agent_service: AIAgentService = Depends(get_agent_service)
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):
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await websocket.accept()
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try:
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while True:
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data = await websocket.receive_json()
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message = data.get("message")
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thread_id = data.get("thread_id", str(uuid.uuid4()))
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model = data.get("model", "zhipu")
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user_id = data.get("user_id", "default_user")
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if not message:
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await websocket.send_json({"error": "missing message"})
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continue
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reply = await agent_service.process_message(message, thread_id, model, user_id)
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actual_model = model if model in agent_service.graphs else next(iter(agent_service.graphs.keys()))
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await websocket.send_json({"reply": reply, "thread_id": thread_id, "model_used": actual_model})
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except WebSocketDisconnect:
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pass
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# ========== 审核相关端点 ==========
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def review_to_response(review: HumanReview) -> ReviewResponse:
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"""将审核对象转换为响应对象"""
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return ReviewResponse(
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review_id=review.review_id,
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thread_id=review.thread_id,
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user_id=review.user_id,
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status=review.status.name,
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content_to_review=review.content_to_review,
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review_comment=review.review_comment,
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modified_content=review.modified_content,
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created_at=review.created_at.isoformat(),
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reviewed_at=review.reviewed_at.isoformat() if review.reviewed_at else None
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)
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@app.get("/reviews/pending", response_model=list[ReviewResponse])
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async def get_pending_reviews(
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limit: int = Query(100, ge=1, le=500, description="返回数量限制"),
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review_manager: ReviewManager = Depends(get_review_manager)
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):
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"""获取待审核列表"""
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reviews = review_manager.get_pending_reviews(limit)
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return [review_to_response(review) for review in reviews]
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@app.get("/reviews/{review_id}", response_model=ReviewResponse)
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async def get_review(
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review_id: str,
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review_manager: ReviewManager = Depends(get_review_manager)
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):
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"""获取审核详情"""
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review = review_manager.get_review(review_id)
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if not review:
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raise HTTPException(status_code=404, detail="Review not found")
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return review_to_response(review)
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@app.get("/reviews/thread/{thread_id}", response_model=list[ReviewResponse])
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async def get_thread_reviews(
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thread_id: str,
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review_manager: ReviewManager = Depends(get_review_manager)
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):
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"""获取线程的所有审核"""
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# 注意：我们的 ReviewStore 接口目前没有 get_by_thread 方法暴露在 ReviewManager 中
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# 这里我们直接访问 store，但在实际项目中应该在 ReviewManager 中添加这个方法
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reviews = review_manager.store.get_by_thread(thread_id) if hasattr(review_manager.store, 'get_by_thread') else []
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return [review_to_response(review) for review in reviews]
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@app.post("/reviews/{review_id}/approve")
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async def approve_review(
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review_id: str,
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request: ReviewActionRequest,
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review_manager: ReviewManager = Depends(get_review_manager)
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):
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"""审核通过"""
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success = review_manager.approve(
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review_id=review_id,
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reviewer=request.reviewer,
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comment=request.comment
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)
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if not success:
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raise HTTPException(status_code=404, detail="Review not found")
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return {"status": "success", "review_id": review_id}
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@app.post("/reviews/{review_id}/reject")
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async def reject_review(
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review_id: str,
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request: ReviewActionRequest,
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review_manager: ReviewManager = Depends(get_review_manager)
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):
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"""审核拒绝"""
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success = review_manager.reject(
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review_id=review_id,
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reviewer=request.reviewer,
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comment=request.comment
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)
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if not success:
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raise HTTPException(status_code=404, detail="Review not found")
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return {"status": "success", "review_id": review_id}
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@app.post("/reviews/{review_id}/modify")
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async def modify_review(
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review_id: str,
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request: ReviewActionRequest,
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review_manager: ReviewManager = Depends(get_review_manager)
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):
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"""审核修改"""
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if not request.modified_content:
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raise HTTPException(status_code=400, detail="modified_content required")
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success = review_manager.modify(
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review_id=review_id,
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reviewer=request.reviewer,
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modified_content=request.modified_content,
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comment=request.comment
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)
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if not success:
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raise HTTPException(status_code=404, detail="Review not found")
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return {"status": "success", "review_id": review_id}
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@app.post("/reviews/request")
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async def request_review(
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thread_id: str,
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user_id: str,
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content: str,
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review_manager: ReviewManager = Depends(get_review_manager)
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):
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"""请求审核（测试用）"""
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review_id = review_manager.request_review(thread_id, user_id, content)
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return {"status": "success", "review_id": review_id}
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if __name__ == "__main__":
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import uvicorn
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# 使用环境变量或默认端口 8079（避免与 llama.cpp 的 8081 端口冲突）
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port = int(BACKEND_PORT)
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uvicorn.run(app, host="0.0.0.0", port=port)
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