from fastapi import FastAPI, Depends, HTTPException
from fastapi.middleware.cors import CORSMiddleware
from sqlalchemy.orm import Session
from database import get_db
from sql_generator import SQLGenerator
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
app = FastAPI(title="Land Analysis API")
import traceback
# 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,
    db: Session = Depends(get_db)
):
    """
    流式返回土地分析结果
    """
    async def generate_stream() -> AsyncGenerator[str, None]:
        try:
            similar_examples = None
            generated_sql = 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":
                    generated_sql = data["content"]
                    yield chunk
                else:
                    yield chunk

            if not generated_sql:
                yield json.dumps({
                    "type": "error",
                    "message": "SQL生成失败"
                }) + "\n"
                return

            # 执行SQL并返回结果
            result = await sql_generator.execute_sql(generated_sql, db)
            
            if result["status"] == "error":
                yield json.dumps({
                    "type": "error",
                    "message": result["message"]
                }) + "\n"
                return

            # 生成可视化
            df = pd.DataFrame(result["data"])
            visualization = None
            
            if not df.empty:
                if len(df.columns) >= 2:
                    if df.select_dtypes(include=['number']).columns.any():
                        fig = px.bar(df, x=df.columns[0], y=df.columns[1])
                        visualization = json.loads(fig.to_json())

            # 返回最终结果
            yield json.dumps({
                "type": "result",
                "data": {
                    "sql": generated_sql,
                    "data": result["data"],
                    "visualization": visualization,
                    "similar_examples": similar_examples
                }
            }) + "\n"

        except Exception as e:
            traceback.print_exc()
            yield json.dumps({
                "type": "error",
                "message": str(e)
            }) + "\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,
    db: Session = Depends(get_db)
):
    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, db)
        
        if result["status"] == "error":
            raise HTTPException(status_code=400, detail=result["message"])
        
        # 生成可视化
        df = pd.DataFrame(result["data"])
        visualization = None
        
        if not df.empty:
            if len(df.columns) >= 2:
                if df.select_dtypes(include=['number']).columns.any():
                    fig = px.bar(df, x=df.columns[0], y=df.columns[1])
                    visualization = json.loads(fig.to_json())
        
        return AnalysisResult(
            sql=sql,
            data=result["data"],
            visualization=visualization,
            similar_examples=similar_examples
        )
    
    except Exception as e:
        traceback.print_exc()
        raise HTTPException(status_code=500, detail=str(e))

if __name__ == "__main__":
    uvicorn.run(app, host="0.0.0.0", port=8001)