from fastapi import FastAPI
from contextlib import asynccontextmanager
import uvicorn
from pathlib import Path
from downloader import router as downloader_router

# 检查并创建 downloads 目录
def ensure_downloads_dir():
    downloads_dir = Path("downloads")
    downloads_dir.mkdir(exist_ok=True)
    print(f"确保 downloads 目录存在: {downloads_dir.absolute()}")

#  lifespan 事件处理器
@asynccontextmanager
async def lifespan(app: FastAPI):
    # 启动时执行
    ensure_downloads_dir()
    print("应用启动完成！")
    yield
    # 关闭时执行（可选）
    print("应用正在关闭...")

app = FastAPI(
    title="下载器API",
    description="一个基于FastAPI的异步下载器服务",
    version="1.0.0",
    lifespan=lifespan
)

# 注册路由
app.include_router(downloader_router)

@app.get("/")
async def root():
    return {"message": "下载器服务运行中", "status": "healthy"}

if __name__ == "__main__":
    uvicorn.run(
        "main:app",
        host="0.0.0.0", 
        port=5100,
        reload=True  # 开发时自动重载
    )