import os
from dotenv import load_dotenv
from types import MappingProxyType


def get_cfg(env='qa'):
    environment_name = os.getenv('ENV_NAME', env)
    dotenv_path = f'.env.{environment_name}'
    if not os.path.exists(dotenv_path):
        raise FileNotFoundError(f"{dotenv_path} does not exist")
    load_dotenv(dotenv_path)

    config_dict = {
        'client_id': os.getenv('CLIENT_ID'),
        'client_secret': os.getenv('CLIENT_SECRET'),
        'token_url': os.getenv('TOKEN_FETCH_URL'),
        'username': os.getenv('USERNAME'),
        'password': os.getenv('PASSWORD'),
        'audience': os.getenv('AUDIENCE'),
        'scopes': os.getenv('SCOPES', '').split(','),
        'api_url': os.getenv('API_URL')
    }
    config = MappingProxyType(config_dict)  # immutable dict
    return config