343 lines
11 KiB
Python
343 lines
11 KiB
Python
"""
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Python Flask/FastAPI 服务器实现，用于替代 Node.js 服务器
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使用 DashScope Python SDK 连接阿里云百炼平台 API
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"""
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import os
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import json
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import uuid
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import asyncio
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from datetime import datetime
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from typing import Dict, List, Optional
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from pathlib import Path
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import dashscope
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from dashscope import Generation
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from dotenv import load_dotenv
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from fastapi import FastAPI, HTTPException, File, UploadFile, Form
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from fastapi.responses import JSONResponse, StreamingResponse
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from pydantic import BaseModel, Field
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import uvicorn
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# 加载环境变量
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load_dotenv()
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# 设置 DashScope API 密钥
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dashscope.api_key = os.getenv("ALIYUN_API_KEY")
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# 创建 FastAPI 应用
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app = FastAPI(title="AI Chat API Server", version="1.0.0")
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# 数据模型定义
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class ChatMessage(BaseModel):
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role: str
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content: str
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images: Optional[List[str]] = None
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files: Optional[List[str]] = None
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class ChatRequest(BaseModel):
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conversationId: Optional[str] = None
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message: str
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images: Optional[List[str]] = None
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files: Optional[List[str]] = None
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model: Optional[str] = "qwen-plus"
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temperature: Optional[float] = 0.7
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maxTokens: Optional[int] = 2000
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systemPrompt: Optional[str] = "你是一个支持视觉理解的助手。"
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stream: Optional[bool] = True
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# 扩展选项
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deepSearch: Optional[bool] = False
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webSearch: Optional[bool] = False
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deepThinking: Optional[bool] = False
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class ModelInfo(BaseModel):
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id: str
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name: str
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description: str
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maxTokens: int
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provider: str
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# 模拟数据库 - 实际应用中应使用持久化存储
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conversations_db: Dict[str, dict] = {}
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# 配置上传目录
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upload_dir = Path("uploads")
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upload_dir.mkdir(exist_ok=True)
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@app.middleware("http")
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async def add_process_time_header(request, call_next):
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"""中间件：记录请求处理时间"""
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start_time = datetime.utcnow()
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response = await call_next(request)
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# 计算处理时间
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process_time = (datetime.utcnow() - start_time).total_seconds() * 1000
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# 在响应头中添加处理时间
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response.headers["X-Process-Time"] = f"{process_time:.2f}ms"
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# 记录请求信息
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print(f"HTTP {request.method} {request.url.path} {response.status_code} {process_time:.2f}ms")
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return response
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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"""
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return {"status": "healthy", "timestamp": datetime.utcnow().isoformat()}
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@app.post("/api/chat-ui/chat")
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async def chat_endpoint(request: ChatRequest):
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"""聊天接口 - 处理普通请求"""
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try:
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# 构建消息数组，考虑是否包含图片
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user_content = []
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# 添加用户消息文本
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user_content.append({"type": "text", "text": request.message})
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# 如果有图片，则添加到内容中
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if request.images and len(request.images) > 0:
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for image_url in request.images:
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user_content.append({
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"type": "image_url",
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"image_url": image_url
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})
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# 构建请求给百炼的消息列表
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messages = [
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{"role": "system", "content": request.systemPrompt},
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{"role": "user", "content": user_content}
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]
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# 调用 DashScope API
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response = Generation.call(
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model=request.model,
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messages=messages,
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stream=False, # 非流式响应
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max_tokens=request.maxTokens,
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temperature=request.temperature
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)
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if response.status_code == 200:
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content = response.output.choices[0]['message']['content']
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# 构建响应
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result = {
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"id": str(uuid.uuid4()),
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"conversationId": request.conversationId or str(uuid.uuid4()),
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"content": content,
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"model": request.model,
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"createdAt": int(datetime.utcnow().timestamp())
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}
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if hasattr(response, 'usage'):
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result["usage"] = {
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"promptTokens": response.usage.input_tokens,
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"completionTokens": response.usage.output_tokens,
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"totalTokens": response.usage.total_tokens
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}
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return JSONResponse(content=result)
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else:
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raise HTTPException(status_code=500, detail=f"API Error: {response.code} - {response.message}")
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except Exception as e:
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print(f"Error in chat endpoint: {str(e)}")
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raise HTTPException(status_code=500, detail=str(e))
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@app.post("/api/chat-ui/chat/stream")
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async def chat_stream_endpoint(request: ChatRequest):
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"""流式聊天接口 - 处理流式请求"""
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async def event_generator():
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try:
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# 构建消息数组，考虑是否包含图片
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user_content = []
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# 添加用户消息文本
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user_content.append({"type": "text", "text": request.message})
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# 如果有图片，则添加到内容中
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if request.images and len(request.images) > 0:
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for image_url in request.images:
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user_content.append({
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"type": "image_url",
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"image_url": image_url
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})
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# 构建请求给百炼的消息列表
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messages = [
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{"role": "system", "content": request.systemPrompt},
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{"role": "user", "content": user_content}
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]
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# 调用 DashScope API（流式）
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responses = Generation.call(
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model=request.model,
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messages=messages,
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stream=True, # 流式响应
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max_tokens=request.maxTokens,
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temperature=request.temperature
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)
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for response in responses:
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if response.status_code == 200:
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content = response.output.choices[0]['message']['content']
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if content:
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# 发送流式数据
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data = {
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"choices": [
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{
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"delta": {"content": content},
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"index": 0,
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"finish_reason": None
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}
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]
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}
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yield f"data: {json.dumps(data)}\n\n"
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else:
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error_data = {
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"error": {
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"message": f"API Error: {response.code} - {response.message}",
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"type": "api_error",
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"param": None,
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"code": response.code
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}
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}
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yield f"data: {json.dumps(error_data)}\n\n"
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break
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# 发送结束信号
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yield "data: [DONE]\n\n"
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except Exception as e:
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error_data = {
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"error": {
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"message": str(e),
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"type": "server_error"
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}
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}
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yield f"data: {json.dumps(error_data)}\n\n"
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return StreamingResponse(event_generator(), media_type="text/event-stream")
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@app.get("/api/chat-ui/models")
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async def get_models():
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"""获取模型列表"""
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models = [
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ModelInfo(
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id="qwen-max",
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name="通义千问 Max",
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description="最强大的模型",
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maxTokens=8192,
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provider="Aliyun"
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),
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ModelInfo(
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id="qwen-plus",
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name="通义千问 Plus",
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description="能力均衡",
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maxTokens=8192,
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provider="Aliyun"
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)
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]
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return [model.dict() for model in models]
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@app.get("/api/chat-ui/conversations")
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async def get_conversations():
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"""获取所有对话"""
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return list(conversations_db.values())
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@app.get("/api/chat-ui/conversations/{conversation_id}")
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async def get_conversation(conversation_id: str):
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"""获取特定对话"""
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conversation = conversations_db.get(conversation_id)
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if not conversation:
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raise HTTPException(status_code=404, detail="对话不存在")
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return conversation
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@app.post("/api/chat-ui/conversations")
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async def save_conversation(
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id: str = Form(None),
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title: str = Form(...),
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messages: str = Form(...)
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):
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"""保存或更新对话"""
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# 解析 messages JSON 字符串
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try:
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parsed_messages = json.loads(messages)
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except json.JSONDecodeError:
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raise HTTPException(status_code=400, detail="Invalid messages JSON")
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conversation_id = id or str(uuid.uuid4())
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conversation = {
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"id": conversation_id,
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"title": title,
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"messages": parsed_messages,
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"updatedAt": datetime.utcnow().isoformat()
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}
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conversations_db[conversation_id] = conversation
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return conversation
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@app.delete("/api/chat-ui/conversations/{conversation_id}")
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async def delete_conversation(conversation_id: str):
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"""删除对话"""
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if conversation_id in conversations_db:
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del conversations_db[conversation_id]
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return {"success": True, "message": "删除成功"}
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else:
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raise HTTPException(status_code=404, detail="对话不存在")
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@app.post("/api/chat-ui/upload")
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async def upload_file(file: UploadFile = File(...)):
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"""文件上传接口"""
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try:
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# 生成唯一文件名
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file_extension = Path(file.filename).suffix
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unique_filename = f"{int(datetime.utcnow().timestamp())}-{uuid.uuid4()}{file_extension}"
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file_path = upload_dir / unique_filename
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# 保存文件
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with open(file_path, "wb") as f:
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content = await file.read()
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f.write(content)
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# 返回文件信息
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file_url = f"http://localhost:8000/uploads/{unique_filename}"
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return {
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"url": file_url,
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"name": file.filename,
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"size": len(content),
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"mimeType": file.content_type
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}
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except Exception as e:
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print(f"Upload error: {str(e)}")
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raise HTTPException(status_code=500, detail=f"上传失败: {str(e)}")
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@app.get("/uploads/{filename}")
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async def serve_upload(filename: str):
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"""提供上传文件的访问"""
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file_path = upload_dir / filename
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if not file_path.exists():
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raise HTTPException(status_code=404, detail="文件不存在")
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from fastapi.responses import FileResponse
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return FileResponse(file_path)
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@app.post("/api/chat-ui/stop")
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async def stop_generation():
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"""停止生成接口"""
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# 在实际实现中，这里可能需要维护正在运行的任务ID列表
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# 目前只是返回成功消息
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return {"success": True, "message": "已发出停止指令"}
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@app.post("/api/chat-ui/stop/{message_id}")
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async def stop_generation_by_id(message_id: str):
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"""根据消息ID停止生成"""
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return {"success": True, "message": "已发出停止指令"}
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if __name__ == "__main__":
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port = int(os.getenv("PORT", 8000))
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uvicorn.run(app, host="0.0.0.0", port=port) |