import json
import traceback

OK = '{"ok":true}'

def ok_playlist(items: list[str]) -> str:
    return json.dumps({
        "ok": True,
        "data": items,
    })

def ok_download(ret: int) -> str:
    return json.dumps({
        "ok": True,
        "data": ret,
    })

def error(ex: Exception) -> str:
    traceback.print_tb(ex.__traceback__)
    return json.dumps({
        "ok": False,
        "error": {
            "type": ex.__class__.__qualname__,
            "message": str(ex),
        }
    })