from posting import Auth, Header, RequestModel, Posting
import httpx

def get_oauth2_token(client_id, client_secret, token_url, audience):
    """
    Request an OAuth2 access token using the Client Credentials Grant flow.

    Args:
        client_id (str): The client ID provided by the OAuth2 provider.
        client_secret (str): The client secret provided by the OAuth2 provider.
        token_url (str): The URL to request the access token.

    Returns:
        str: The access token if the request is successful.
    """
    # Prepare the data for the token request
    data = {
        "grant_type": "client_credentials",  # Grant type for Client Credentials flow
        "client_id": client_id,
        "client_secret": client_secret,
        "audience": audience
    }

    try:
        # Make the POST request to the token endpoint
        response = httpx.post(token_url, data=data)

        # Raise an exception if the request failed
        response.raise_for_status()

        # Parse the JSON response
        token_data = response.json()

        print ("Successfully obtained access_token")

        # Return the access token
        return token_data.get("access_token")
    except httpx.RequestError as e:
        print(f"An error occurred while requesting the token: {e}")
    except httpx.HTTPStatusError as e:
        print(f"HTTP error occurred: {e.response.status_code} - {e.response.text}")
    except KeyError:
        print("The response did not contain an access token.")
    return None

def setup(posting: Posting) -> None:
    if not posting.get_variable("auth_token"):
        token = get_oauth2_token(posting.variables["CLIENT_ID_V2"], posting.variables["CLIENT_SECRET_V2"],posting.variables["TOKEN_URL"],posting.variables["AUDIENCE"],)
        posting.set_variable("auth_token", token)