from fastapi import FastAPI, File, UploadFile, HTTPException, APIRouter
import asyncio
from sqlalchemy.dialects.sqlite import insert
from pathlib import Path
import pandas as pd
from typing import List
from sqlmodel import select, SQLModel, Session
from mylib.logu import logger
from worker.search_engine.search_result_db import SearchResultManager, KeywordTask
from fastapi.responses import JSONResponse
from io import BytesIO
from config.settings import DB_URL

app = APIRouter()

@app.get("/tasks/statistics", summary="获取任务统计信息")
async def get_task_statistics():
    try:
        db_manager = SearchResultManager()
        stats = db_manager.get_task_statistics()
        return JSONResponse(content=stats)
    except Exception as e:
        logger.error(f"获取统计信息失败: {str(e)}")
        raise HTTPException(status_code=500, detail=str(e))

@app.post("/upload", 
          summary="导入关键词文件",
          description="支持Excel和CSV文件，读取第一列作为关键词")
async def import_keywords(file: UploadFile = File(...)):
    try:
        db_manager = SearchResultManager()
        logger.info(f"数据库连接: {DB_URL}")
        
        # 异步读取文件内容并使用线程池处理
        content = await file.read()
        loop = asyncio.get_event_loop()
        
        # 在线程池中处理文件读取
        file_path = Path(file.filename)
        df = await loop.run_in_executor(
            None, 
            lambda: pd.read_excel(BytesIO(content), header=0) if file_path.suffix.lower() in ('.xlsx', '.xls') 
            else pd.read_csv(BytesIO(content), sep='\t' if file_path.suffix == '.tsv' else ',')
        )
        keywords = df.iloc[:, 0].astype(str).tolist()
        
        # 在另一个线程中处理数据库插入
        inserted_count = await asyncio.to_thread(
            bulk_import_keywords_to_db, 
            keywords, 
            db_manager
        )
        
        return JSONResponse(content={
            "total_keywords": len(keywords),
            "inserted_count": inserted_count,
            "message": "导入成功"
        })
        
    except Exception as e:
        logger.error(f"文件处理失败: {str(e)}")
        raise HTTPException(status_code=500, detail=str(e))


def bulk_import_keywords_to_db(keywords: List[str], db_manager: SearchResultManager):
    """
    使用 SQLite 的 UPSERT 语法进行批量插入，避免重复
    """
    try:
        with Session(db_manager.engine) as session:
            # 使用 SQL 原生批量插入语法
            stmt = insert(KeywordTask).values(
                [{"keyword": kw} for kw in keywords]
            ).on_conflict_do_nothing(index_elements=["keyword"])
            
            # 执行批量插入
            result = session.exec(stmt)
            session.commit()
            
            # 获取实际插入数量
            inserted_count = result.rowcount
            
            logger.info(f"成功导入 {inserted_count} 个新关键词")
            return inserted_count
            
    except Exception as e:
        logger.error(f"批量导入失败: {str(e)}")
        if 'session' in locals():
            session.rollback()
        raise