import os
from types import MappingProxyType

from dotenv import dotenv_values

PROJECT_ROOT = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))

# Dict to hold values from dotenv files; keys are filenames, values are dictionaries of env vars
_dotenv_values = {}


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

    if dotenv_path not in _dotenv_values or force_refresh:
        # Load the env vars from the dotenv file and store them in the _dotenv_values dict
        _dotenv_values[dotenv_path] = dotenv_values(dotenv_path)

    # Now, we're sure that _dotenv_values[dotenv_path] contains up-to-date env vars from dotenv_path
    dotenv_vars = _dotenv_values[dotenv_path]

    config_dict = {
        'client_id': dotenv_vars.get('CLIENT_ID'),
        'client_secret': dotenv_vars.get('CLIENT_SECRET'),
        'token_url': dotenv_vars.get('TOKEN_FETCH_URL'),
        'login': dotenv_vars.get('LOGIN'),
        'password': dotenv_vars.get('PASSWORD'),
        'audience': dotenv_vars.get('AUDIENCE'),
        'scopes': dotenv_vars.get('SCOPES', '').split(','),
        'api_url': dotenv_vars.get('API_URL')
    }
    config = MappingProxyType(config_dict)  # immutable dict
    return config