CSPON-TSC/landsite_agent/main.py

from fastapi import FastAPI, HTTPException
from fastapi.middleware.cors import CORSMiddleware
from pydantic import BaseModel
import pandas as pd
import plotly.express as px
import json
from fastapi.responses import StreamingResponse
from typing import AsyncGenerator, List, Dict, Any
import uvicorn
import traceback
import asyncio
from xuanzhi_query import router as xz_router
from sql_generator import SQLGenerator

app = FastAPI(title="Land Analysis API")
app.include_router(xz_router)
# 配置CORS
app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)


class QueryRequest(BaseModel):
    description: str


class AnalysisResult(BaseModel):
    sql: str
    data: list
    visualization: dict = None
    similar_examples: List[Dict[str, Any]] = None


sql_generator = SQLGenerator()


@app.post("/land_analysis/stream")
async def stream_land_analysis(request: QueryRequest):
    """
    流式返回土地分析结果
    """

    async def generate_stream() -> AsyncGenerator[str, None]:
        try:
            similar_examples = None

            # 流式生成SQL
            async for chunk in sql_generator.generate_sql_stream(request.description):
                data = json.loads(chunk)

                if data["type"] == "similar_examples":
                    similar_examples = data["content"]
                    yield chunk
                elif data["type"] == "sql_generation":
                    yield chunk
                elif data["type"] == "sql_result":
                    # 获取到完整的SQL后执行
                    sql = data["content"]
                    result = await sql_generator.execute_sql(sql)

                    if result["status"] == "error":
                        yield json.dumps({
                            "type": "error",
                            "content": result["content"]
                        }, ensure_ascii=False) + "\n"
                        return

                    # 返回最终结果
                    yield json.dumps({
                        "type": "result",
                        "data": {
                            "sql": sql,
                            "exec_result": result["data"]
                        }
                    }, ensure_ascii=False) + "\n"
                else:
                    yield chunk

        except Exception as e:
            traceback.print_exc()
            yield json.dumps({
                "type": "error",
                "content": str(e)
            }, ensure_ascii=False) + "\n"

    return StreamingResponse(
        generate_stream(),
        media_type="text/event-stream"
    )


@app.post("/land_analysis", response_model=AnalysisResult)
async def generate_and_execute_sql(request: QueryRequest):
    try:
        # 获取相似示例
        similar_examples = sql_generator._get_similar_examples(request.description)

        # 构建增强提示词
        enhanced_prompt = f"""
        基于以下相似示例：
        {json.dumps(similar_examples, ensure_ascii=False, indent=2)}
        
        请根据以下描述生成SQL查询：
        {request.description}
        """

        # 生成SQL
        sql = await sql_generator.chain.arun(enhanced_prompt)

        # 执行SQL
        result = await sql_generator.execute_sql(sql)

        if result["status"] == "error":
            raise HTTPException(status_code=400, detail=result["message"])

        return AnalysisResult(
            sql=sql,
            exec_result=result["data"]
        )

    except Exception as e:
        traceback.print_exc()
        raise HTTPException(status_code=500, detail=str(e))


@app.on_event("shutdown")
async def shutdown_event():
    """
    应用关闭时清理资源
    """
    await sql_generator.close()


if __name__ == "__main__":
    uvicorn.run(app, host="0.0.0.0", port=8521)