from typing import Tuple
import platform


def _mongo_ver() -> Tuple[str, str]:
    """Return mongo version based on platform system."""
    if platform.system() == 'Linux':
        mongo_exec = "linux", 'mongodb-linux-x86_64-ubuntu1804-4.4.6'
    elif platform.system() == 'Darwin':
        mongo_exec = "osx", 'mongodb-macos-x86_64-4.4.6'
    else:
        raise Exception("Unsupported platform")

    return mongo_exec